Thats one of the other things im concerned about. I dont know the ins and outs of the legal system regarding contracts and such. I have a general model release that I have had people sign so that I can use their images on a website or my flickr page or whatever, but all the legalities worry me. Is there a good site that I can do some reading on that differentiates contracts or explains the contracts I should be worried/aware of?
The problem with the advice (legal, or otherwise) that you get over the internet, is that it's, well, the internet.
You might consider having a brief (one hour -- ??) consultation with a lawyer in your area. They would be in a better position to offer you *real* advice on such matters.
There comes a time when it is best to let the experts do their thing (that's why they exist). Personally, legal matters, taxes, accounting, etc. are all prime candidates for hiring experts. IMO, it is usually money well spent.
Buy a copy of Business and Legal Forms for Photographers by Tad Crawford. This is part of the materials available from ASMP. It is not a replacement for personal legal advice, but photography and copyright are special areas of business law and not every attorney will be prepared to advise you on them. The book is available from all the big booksellers.
Most attorneys will not know.
Having said that. You need a model or property release for any photograph that will be used commercially unless it is a news event (whatever that truly means). Here is the kicker. If the photograph is for artistic use then you don't need a model release. So any photographs that are printed and go on the wall, or into art type books don't need a model or property release. Now here is a kicker, you better have a model and property releases for the photographs on the cover of a book as they are often used in advertising the book. That is a commercial use. What does that tell you? To me it means get the release if at all possible. News events are another no model release needed situation, but don't try to sell that photo for a commercial use like in advertising. A photo along with a news article, in a history book, or book of news photographs is fine. Commercial use, no, then you need the model release. What makes a news event, that can be a bit murky, but if there is another non event hired news photographer or reporter there working you can be pretty sure it is a news event. Tag all your photographs with source information and if there is a model and/or property release. This is important for how they can be used later. This is only a short and very incomplete introduction as to how various photographs can and can't be used.
As for copyright, unless you signed it away under contract it is yours. When you take photographs at a club, use your own contract that keeps the photograph copyrights as yours. Same goes for any other event. If somebody wants the copyrights, charge them through the nose for them. The studio I worked for in the early 80's charged at the minimum 10 times their normal daily rate of $2400 a day if the client wanted copyrights and some paid it.