Buying a used macbook

[!Yaminashi]

Hey guys,

Long story short I might be buying a used macbook.
My question is, what things should I check on the laptop itself?

Is there some sort of menu i can access that tells me that everything is working properly?

As you can see I'm not too tech savvy

[Xander]

You can pop in the Recovery CD and hold a key to perform a system diagnostic (it'll say what key on top of the recovery cd) I'm not sure how well it works but it's an option.