If you want a forum, here's some advice..
Never use invisionfree/proboards. Or other things, such as phpBBforfree. Not only do they make your site look like a cheap piece of crap, but they are littered with adverts and you have no control over your MySQL data
Never make forum-only sites. Everybody hates them. If your site is an invisionfree forum-only "site", you may as well close it down.
Always install forums on your own webspace. That way you have total control over your forum, even over your MySQL data. And if you want to convert your forum to a different system (ie. phpBB to vBulletin) then it's possible to do it.
Never allow guests to post. It makes things easier for the spammers and n00bs.
Make your own skin if you can. Making your own skin is the best option, you can make the skin look like your site! If not, then you'll have to do a lot of searching to find a good theme. Many people, especially those who use vBulletin, make thier own skins.
Never hire anonymous staff. If you say something like "first one to register becomes a mod!!" then withdraw your comment, and if somebody requests to be a mod, refuse them. You don't want strangers screwing up your board, instead hire people who are active, mature and trustworthy. If your forum is just starting out you don't need a whole moderating team, one admin (you) will do just fine. As your forum gets bigger, hire a couple of people.