Small Business Association
In the organization's own words, "The U.S. Small Business Administration (SBA) was created in 1953 as an independent agency of the federal government to aid, counsel, assist and protect the interests of small business concerns, to preserve free competitive enterprise and to maintain and strengthen the overall economy of our nation."
The small business association homepage is not going to provide you with lesson plans or anything so directly applicable to the history classroom. However, what it does offer is nothing to scoff at.
Do you teach business history at all during your courses? If so, you might find the site's collection of HTML, text, and PDF files of laws applicable to small business useful in discussing the changes in workplace expectations over time.
If your students find the vocabulary of business daunting, the SBA has developed a handy one-stop resource in the form of a glossary. There's no reason to Wikipedia search confusing acronyms when a reliable .gov site exists to answer your questions.
A final option is to ask your students to write their own business plans based on the SBA's guidelines and sample plans (an external link from the SBA page). The activity may help students to grasp both the difficulties facing small business owners, as well as the personal freedom and expression which has drawn individuals to business ownership throughout time.