Well I have a upload site where people can upload files, I feel that I should have some sort of Terms Of Service. How do I create a terms of service? Does it have to be a certain length?
I am no expert but I would imagine that not only you will need a solid TOS but also actions to enforce it. An easy way to report or flag an offensive or illegal material will probably help you too. You will also need to monitor it somehow. Look at the big ones for examples - YouTube, Rapidshare, etc. The best way to think of it is - imagine you are a public storage place that's free and you make money from advertisement... Now if someone's stuff get stolen or someone get hurt on site, upset people may sue you. Regardless of TOS and the fact it's free. Now if you had cameras in place and guards on site, people would feel better and would have a harder time suing because it's not like you didn't take any actions.
Outline the all the possible terms you want to include and then write the details. As far as length is concerned, I don't think so that TOS has some length oriented issue, it all depends on your requirements.
rapidshare and megashare are doing the same biz...you can have a look at their Terms page..so that you'll get some idea..
You should have a TOS, its important to protect yourself. I Have a ten page one I drafted if you want to take a look, p.m me for details.