Setting permission for specific pages/forms?

I decided to use Drupal on a recent project and I couldn't figure out how to make a simple roster that linked to the WoWArmory. So I went ahead and wrote my own form and php to process everything. I took all of that code and put it in a new page. Works just fine, except for the fact that ANYONE can see the form(the form adds names to the list, which is on the same page). I don't mind that anonymous can see the roster...but the form isn't good because someone could just spam it with all sorts of names and what not.

So how do I allow either
1. (simple way) Only certain roles to view this page(i.e both the list of names and the form).
2. How do I allow only certain roles to view the form but allow anonymous to view the roster

Hope that clear enough.

Normally I'd wrap if(isset('$_SESSION['username']')){ // code here //} but I don't think thats how it works in drupal.... =/