Need Help

Hi I wanted to ask you guys and gals a question, i respect your knowledge. I am a jail administrator of a county jail in kentucky and i know how important and valuable it is to be able to share and pick other people that is in same profession's brain. I was wanting to start a subscription based forum that would deal with issues that jail administrators have to deal with everyday. Share problem solving with each other maybe forms we use just a good information site where we can discuss issues we deal with. What i would like to know is what is the best way to start this the cheapest way and how much detail do i need in a site , i would like to sell advertising from vendors in our industry to make some money also. Should i have some of the forum free? and then paying members get more access to other info? I would like a forum host that has some neat capibilities like posting videos and articles things like that. Just wondering how to start and if you all could give me some resources online that could help me. I really know nothing about setting up website or forum. Thansk in advance.