I installed WebCit but when I try to connect with my browser it doesn't log in. Why?

WebCit doesn't run by itself. You must first install the Citadel server, get it running the way you want it, and try putting WebCit in front of it. WebCit doesn't run the system by itself; it merely puts a web front-end on the Citadel server. You need both in order to have a presence on the web.