Business model and legal rundown on freelance press work?

I'm looking to take on the occasional assignment for a local paper. Can somebody please give me a brief run-down on what to expect as far as rights, legal rights, paperwork, releases are concerned?

How does the pay structure usually work on assignment gigs for local papers? What are reasonable expectations in the North-East U.S.?

I've build a decent resume (I think) of local business and political and charity events, some junior sports (not my favorite) and concerts. Even though I have a good full-time job I feel it's time to move on and make a little side-money from one of my passions.

Thanks, 7