Legal info and scripting support

Dear friends,
I am not a webmaster myself but have come to you for your help and support.
I am in the process of starting a website for the college i used to be in, as a part of the alumni activity.

The idea is to form a community website for all the students who are, or were, from that college. to share stories, experiences, pictures, discussions etc. along with that i want to be able to share music and videos to be able to get outside traffic also, to keep the site commercially running, coz i know its gonna need money to keep it going, so advertisements and other forms of revenue generation are inevitable. on the site i also want a page where people who are looking for jobs or know about jobs available can post the requirements.

along with all of this i want to include a points system which encourage users to participate in activities online using the site. like maybe 2 points for posting in a forum discussion or 5 points for writing an article and 2 points for posting about it or something like that. and maybe later on offer gifts to the point leaders..

can someone help me with this.. even if not technical support can someone at least help me with the legal aspect of it? i am worried about the music and videos aspect of it as i have heard there are strict laws governing that. in that case, what kind of licenses or copyrights etc will i be needing?

thank you for all your help in advance.

My name is Jay and if anyone wants to get in touch with me personally my email id is
[email protected]

Regards
JB