Are you trying to do this clicking and logging in and so forth on an existing site, or are you wanting to DESIGN such a system where people log in to YOUR site? If you're wanting to DESIGN a system for your site, I'd say you have a lot to learn before you can really ask any intelligent questions. How to design web sites isn't really a question, it's a book. For example, you want to make some links. Ok, Google "HTML tutorial" or pick up a copy of "HTML for Dummies" or whatever. After you've been designing web sites for several years and have read a couple of programming books and several security books, you might be ready to think about designing your own security system for people to log in. Until then, get the security system from someone who knows how to security correctly.