Help Wont boot up, stuck on boot up animations

[aaps59]

Hi, hope Im not double posting or anything, but I havent found a solution to my problems yet.
I recently purchased Nexus S 4G, thinking it was working, but it is not. It powers up, but doesn't get to the main system. It sticks on the Nexus colorful flashing things and wont get past that. Sometimes it sticks on the Google logo. Is there anything I can check, or somehow restore it or something to get it to boot up?

 

[aaps59]

Ok update:
I dont know what I did, but I left it plugged in for about an hour to my computer, and its giving me this screen. The nexus animations never came on, and there was no boot logo, it was straight to this:

BTW:
As you might guess, I am slightly new to Android.