MacBook Not Working?

So, I've been having problems with my MacBook for a while now, but thats a whole 'nother story. Today, I tried to start it up, and everything seemed normal, then it got to the part with the little box that says welcome to macintosh and the progress bar fills, then I get that blue screen with a pointer where normally the desktop would load after a second. However, it doesn't load. It stays on the blue screen. What do I do now? All I tried was resetting the PRAM. Any suggestions?