The websites I would recommend:
- www.bulletfilm.com - Is it not obvious? :)
- www.shootingpeople.net - You have to pay 30 UK pounds a year to be a member but you can advertise as well as have access to other filmmakers/actors.
- www.mandy.com - This is a film-networking site. You don't have to pay for the first 28 days, after that you do. Many people use this website for advertising.
Use also as many film related forums as you can. This is another very good way of getting hold of people. Many large social websites have film groups where you could also advertise for crewmembers and actors.
Film schools are another very useful place to look for people. Even if you don't go to one, you can always go and either work on somebody else's production or ask the students to help you out. This is a good way of both: getting to know people and getting work experience.
The actors are always difficult to find. However the Internet is a very useful tool when it comes to this task. There are also many websites where actors post their CV's.
Theatre schools are also a good way to advertise for actors. However, not every acting school is willing to co-operate if you are not wiling to pay the actors. I always find small independent theatres very useful and full of talented people.
What I found over the years is truth is that it's enough to know just one actor and he or she will always bring along others. This works the best for me. Remember, actors need as much exposure as you do.
Keep in mind that if you are not paying people, offer them food on the set and travel expenses as well as a copy of the film once it is finished. And be honest, keep to your word.
And last but definitely not least, regardless whether you pay people or not, always sign contracts. With contracts signed many unpleasant situations can be avoided. Remember, people are just people and you as a creator/director or producer must have the right to do with your project what you wish to do, without having to be afraid that someone might sue you one day.
