I was playing on my X box 360 and this little red light comes on by the power button, after that I can't play or nothing but if I turn it off then turn it back on I can still play for some time(like 5 minutes). What's wrong with it?

You've got the "red circles of death" You need to get out the info for the company and call their tech support. Your 360 is broken and won't work till you get it fixed. I hope you kept all that info because they will fix it for you for free. It's under warenty. What happened is the 360 (non elite) has a cooling problem. The system gets too hot and a sodder from the computer chip melts and the chip falls off.

Kingofkings is spot on, here is some more info from the fabulous wikipedia;

Xbox 360 technical problems - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Xbox_360_technical_problems)