We are a small business with a variety of Internet sites.
This Fall we plan to hire a number of college students to work on our sites.
They will have access to significant proprietary information and business ideas.
We plan to hire them as Free-lance independent contactors.
But, then someone suggested that we hire them as employees so that all
their work and propietary information stays within the company.
What are the risks we take and how can we protect ourselves?
Also, what kind on confidentiality agreement should we have them sign.
Is it different if they are Free-lancers or employees? 
Obviously, hiring them as employees is more complicated.  But is it
the wisest thing to do in the long run?

Consult a Business lawyer for advice on a Non disclosure, and none
compete, any thing to do with espionage or selling your information to
competitors.