The Writers’ Guild of Great Britain has produced a good practice guide to writing film. It’s aimed both at screenwriters and people who work with them, and contains information on practical stuff like contracts, all in one place. And whilst I’ll openly admit I’m not currently in a position where anyone’s asking me to sign contracts for my writing, I like to think it can’t hurt to be informed on this sort of thing.
The guide was posted out to Guild members with the latest quarterly magazine, but it’s free of charge as a PDF, which you can download here, whether or not you’re a member.
Though I’d have to say that it’s not as expensive as you might think to join the Writers’ Guild (just over £8 per month for Candidate Members, which covers folks like me), so it’s worth thinking about, wouldn’t you say?