First, a bit of background. Ever since I've had this car (83 Z28 383 Stroker) it has cranked really slowly but has started every time. But last night when I tried to start it to leave work, it cranked real slow and then stopped and all my lights went out. I had a buddy jump me and then when I turned the key I just got a click. We then tried push starting it - to no avail. Any ideas?

 

Check your 2 main battery cables from the battery to the starter and block / frame.
Remove / clean / tighten

 

Lights going out means that your starter motor is pulling all the current.
Which could mean that your battery is too far gone or that your starter is stuck for some reason.
"Click" means that the starter solenoid can't get the starter motor to do its work, so perhaps that one's fried, too.
After going through vetteoz' suggestions, think about pulling and/or replacing the starter motor.

 

It ended up being a bad connection to the positive terminal on the battery. I got lucky, the guy who towed it home from work was also a Chevy guy, and wanted to look around under the hood just for fun. Saved me $120

 

So I was wasting my time telling you where to look first to sort your problem?

 

No man you were right. I just hadn't had time to look at it. My car was stuck at work (45 min away). I planned on checking all of that stuff when I got it home anyways.
Thank you for your help