Initiatives that welcome the help of volunteers with business management expertise to help in USA communities include the following (these are primarily onsite opportunities; exclusively online opportunities come later):

Goodwill, which helps people who are trying to enter or re-enter the workforce. Goodwill might be able to use your skills in business to mentor one of their clients, to create a class for their clients, to improve the services in their stores, or to introduce a new service in a store. Onsite mentors are sought that can provide help regarding office and clerical jobs, business and financial fields, jobs related to IT (information technology), education jobs, social services fields, customer service, hospitality and food service fields, green jobs, retail work, and health care careers, as well to provide career guidance to people with criminal backgrounds, people with disabilities, young adults, veterans, older workers, women and immigrants.

MicroMentor matches small business owners with business mentors. If you want to be a volunteer mentor, you should have three years of business ownership experience, or five years of management experience, or several years of professional experience in a specialized skill, such as marketing, web site development, accounting, financial planning, etc. The program is part of MercyCorps.

Junior Achievement is a not-for-profit organization whose purpose is to "inspire young people to succeed in a global economy." Volunteers work through JA to teach the importance of workforce readiness, entrepreneurship, and financial literacy. 

Financial Literacy Coalitions, which have branches all over the USA. Use Google to search the phrase Financial Literacy Coalition and the name of your state. Many, though not all, of these coalitions involve volunteers to teach financial literacy skills to young people, families and small businesses.

Local business coalitions, neighborhood business coalitions, neighborhood chambers of commerce, and local business incubators. Use Google, or call your local United Way, to find out if your area has any of these organizations, then contact them and ask if you could help as a volunteer to help small and new businesses serving disadvantaged areas.

VolunteerMatch

Idealist/Action Without Borders

Change.org

All for Good

ServeNet

Network For Good

1-800-Volunteer.org

Do Something

Volunteer Solutions

USAservice.org

International Executive Service Corps (IESC), now includes Geekcorps. Short-term volunteering assignments for USA citizens only. "Promoting Prosperity and Stability through Private Enterprise"

Bpeace.org. This is a USA-based nonprofit that recruits business professionals to help entrepreneurs in countries emerging from war, like Rwanda and Afghanistan, to create and expand businesses and employment (particularly for women). BPEACE believes more jobs mean less violence. Entrepreneurs are engaged in a huge number of business start ups: tailoring, office cleaning, funeral home services, ice cream production, yogurt production, manufacturing of soccer balls, creating and selling building materials, and on and on. Volunteers can mentor entrepreneurs online and even meet with entrepreneurs who come to the USA through Bpeace for short visits.

EnterpriseWorks/VITA."For more than 40 years in 100 countries, EnterpriseWorks/VITA (EWV) has worked to combat poverty by helping small producers and other entrepreneurs build sustainable businesses that create jobs and increase productivity, market opportunities and incomes."

The PeaceCorps and the UN Volunteers program both have a lot of these types of business-support opportunities as well.

There are also lots of "without borders" organizations, like Engineers Without Borders, Télécoms Sans Frontiére and Architects Without Borders. Use Google to find out if there is a "without borders" organization for your area of business expertise.

There are also online opportunities for volunteers with business skills to help people and organizations. Many of the aforementioned organizations allow volunteers to help online - writing press releases, editing business plans, development employee policies and procedures, advising on specialized software purchases (accounting, client tracking, donor tracking, etc.), researching markets, editing fundraising proposals, helping to create staff performance review forms, etc. Many local nonprofits right in your own neighborhood or city will welcome your help, primarily online. There are also some initiatives that recruit online volunteers with business skills specifically:  

Bpeace.org. As noted already on this page, this is a USA-based nonprofit that recruits business professionals to help entrepreneurs in countries emerging from war, like Rwanda and Afghanistan, to create and expand businesses and employment (particularly for women). Entrepreneurs are engaged in a huge number of business start ups: tailoring, office cleaning, funeral home services, ice cream production, yogurt production, manufacturing of soccer balls, creating and selling building materials, and on and on.

Career Village. An online platform where students ask career questions that are answered by people working, or that have worked, in that field. "Share your experiences directly with students on CareerVillage when your schedule permits—whether you're at home or on the road, whether it's day or evening, whether it's a weekday or the weekend. You control what types of questions you want to answer, and how often you are notified of student questions. Your answers can be one sentence or many paragraphs. All you need is a LinkedIn account to start helping students become better informed about the decision they are facing."

Goodwill also has an online mentoring program, GoodProspects: online mentors coach people who are entering or re-entering the work place. Online mentors are sought that can provide help regarding office and clerical jobs, business and financial fields, jobs related to IT (information technology), education jobs, social services fields, customer service, hospitality and food service fields, green jobs, retail work, and health care careers, as well provide career guidance to people with criminal backgrounds, people with disabilities, young adults, veterans, older workers, women and immigrants.

Grow Movement. Online volunteer business consultants from around the world work via Skype, phone and email to empower African entrepreneurs in Uganda, Rwanda and Malawi, helping them with business skills, enabling them to run their organizations more effectively, increase profitability and create jobs in their communities. "Our [online] volunteers are global business professionals with skills in marketing, finance, strategy and business development who offer their 12 consultancy sessions for free."

SCORE, hosts the online community PartnerUp, focused on the needs of small business owners and entrepreneurs. You can volunteer your business expertise to answer questions online from small business owners, entrepreneurs, independent contractors. Online volunteers provide expertise in agriculture and farming, businesses related to arts and entertainment, banking, financial services and insurance, international trade, manufacturing, mining, industry-specific marketing and advertising, real estate, restaurants, transportation, waste management and more. 

There are sometimes business or manufacturing-related professionals needed as online volunteers to mentor people and organizations via the United Nations Online Volunteering Service.

There are also very occasionally such assignments posted to Nabuur, which recruits online volunteers to support organizations working in or for the developing world.

Also see this advice on working abroad for international humanitarian and development agencies), and this resources on volunteering abroad (volunteering internationally).

Also see this very detailed list of organizations that are focused on Online Volunteering / Virtual Volunteering exclusively.

 
If you found this page helpful, let others know:

Other volunteering resources

Tips for Long-Term Unemployed People Seeking Jobs, Older Job Seekers and For Those Just Starting Out

How to Find Volunteering Opportunities, a resource for adults who want to volunteer

Volunteering To Help After Major Disasters.

Home-Based (in your own home) Volunteering Where Your Service is NOT via a Computer or the Internet (at least not to actually DO the volunteering service, but you may need to report your work online).

Volunteering with organizations that help animals and wildlife.

Volunteering In Pursuit of a Medical, Veterinary or Social Work degree / career.

12 Reasons Not to Volunteer Abroad
These are the most common reasons people say they want to volunteer abroad. And they are not good reasons. In fact, they often hurt people and animals in other countries, rather than helping.

Creating or Holding a Successful Community Event or Fund Raising Event.

How to complain about your volunteering experience.

Fund Raising For a Cause or Organization

How to Make a Difference Internationally/Globally/in Another Country Without Going Abroad

How you can advocate for an issue important to you

Finding Community Service and Volunteering for Teens.

Advice for Volunteer Groups / Group Volunteering.

Groups for Atheist and Secular Volunteers

Volunteering with Seniors.

Donating Things Instead of Cash or Time (In-Kind Contributions)

Ideas for Leadership Volunteering Activities
These are more than just do-it-yourself volunteering - these are ideas to create or lead a sustainable, lasting benefit to a community, recruiting others to help and to have a leadership role as a volunteer. These can also be activities for the Girl Scouts Gold Award, the Duke of Edinburgh's Award (U.K.), a mitzvah project, or even scholarship consideration.

Details on how to quickly fill a community service obligation from a court or school.

Ideas for Funding Your Volunteering Abroad Trip.

Careers Working With Animals (for the benefit of animals)

The Last Virtual Volunteering Guidebook available for purchase as a paperback & an ebook
This book is for both organizations new to virtual volunteering, as well as for organizations already involving online volunteers who want to improve or expand their programs. The last chapter of the book is especially for online volunteers themselves.