Apple Thoughts: Time For The Genius Bar? Here Are Some Tips..

"If you work your way through the quick fixes and my other troubleshooting suggestions without success, you'll exhaust your patience. This can easily happen if your Mac's problem lies with its hardware-in most cases, you can't do those repairs yourself. More rarely, you might have a software problem that you can't figure out, despite your best efforts. In either case, the time has arrived for a trip to the Genius Bar."

Just a few tips, mostly basic stuff such as make an appointment and check your warranty, but it never hurts to be prepared. The big one though is make sure its an Apple problem, not a third-party problem. But if you are in doubt, bring it in and if it isn't an Apple problem, they can direct you to the right place.