I'm fairly new to ASP.NET so I'm working on a relatively small web application to get my feet wet.

One thing my project will definitely require is a secure login of some sort. Only certain users should have access to the site, which is going to be on my companies Intranet.

Should I make the user enter a password each and everytime they enter the site, or should I run some sort of authentication that checks their NT account and provides access based on that?

Is one of those methods better than the other? Does the "login control" in Visual Web developer work okay for this?