Lotus Domino - helpme

Ok, hopefully someone can help me. I have a custom website that I want to use a page to authenticate to, not just the normal domino popup. I've seen something about using domcfg.nsf. Do I really need that? I have it setup now so the URL takes you right to my login page. (supplierinfo.mycomp.com) This page seems to work ok. Also, I'm rather a newbie to domino. I was told by support to put my users in an address book (I used pubnames.ntf as the template). How do I use this login form to lookup from the address book? Also, how does domino track this login? Is it all built in or do I need custom code on each page to ensure a user is logged in? Any samples or suggestions would be great! Sorry for all the questions, I'm new to this, I usually develop IIS apps. Thanks!!