Bplans.com
This website is great!  It contains a lot of excellent information on business plans, including definitions, worksheets and online calculators.  This site is a MUST for all of you looking to start your own businesses!
 

Global Entrepreneurship Institute
The entire GEI website is quite helpful, although this particular article is very good.  By summarizing the various stages of entrepreneurship, this article explains what it is like (including the time/effort involved) to create a new business.  Although this article is relatively easy-to-understand, it does use some sophisticated terminology, so be sure to keep a dictionary handy!  
         

IRS-Small Bus/Self-Employed
Although this website it a bit sophisticated, it does offer some good info that you may be able to get from reading through the site.  Straightforward financial information is provided, along with additional areas of interest for new business-owners.

Students for the Advancement of Global Entrepreneurship (SAGE)
SAGE is a great organization that is very involved with promoting entrepreneurship in the secondary school systems.  This site introduces students to the flavor or global business—working with people from different countries.  Competition information is also available.

Teen Startups.com
This section of the entrepreneur.com website has a lot of great info on young entrepreneurship and business.  Since this site is geared towards teens, it is easy to understand and fun to read.  Excellent resources are provided on this site as well.

U.S. Small Business Administration
This site is great for any young person considering starting a new business.  The Small Business Administration site offers tons of info, but the teen site especially gears its information for a younger audience. 

Youngbiz.com
This is a great resource for young, aspiring entrepreneurs and business tycoons!  Visit this site for great business information targeted for today’s youth while also reading about the importance of school on your future careers!
          

Adams, Rob and T.R.
How to be a Teenage Millionaire. 1st ed.  n/a: Entrepreneur Press, 2000.

Offline Entrepreneur Events

Check out your local newspaper, school bulletin, or online listings for a schedule of business events going on in and around your area.  Conferences, seminars, and trade shows are great learning tools for all of you interested in starting your own businesses!

Bhldt, Amar et al. 
Harvard Business Review on Entrepreneurship. Cambridge: Harvard Business School Press, 1999.

Rich, Stanley R.
Business Plans That Win $$$: Lessons from the MIT Enterprise Forum.  Reprint ed. n/a: Perennial Currents, 1987.

Kushell, Jennifer.  
Secrets of the Young & Successful: How to Get Everything You Want Without Waiting a Lifetime.  New York: Fireside, 2003.

Kushell, Jennifer.  
The Young Entrepreneur’s Edge: Using Your Ambition, Independence, and Youth to Launch a Successful Business. 1st ed.  New Jersey: Princeton Review, 1999.