Things to look for:
1)visually look at the engine bay and everything in it look for cracks,leaks anything unusual make a mental note and ask seller about it but common sense can filter bull***t explanations
2)check the body around door jams, rocker panels, and floor pans places where there is alot of stress on the body, knocking on them works well, and if you hear a hollow plastic sound make note of it and tell seller(knock couple hundred off)
3)if you can, get under the car for a better look for leaks i.e. transmission, differential, oil pan also inspect moving parts anything thats under there that you can look at or touch do it.
4)run the car listen to it for squeaks, hisses, loping, pinging, or rubbing, etc.
5)do a compression check, this along with visual inspection and having the engine run and any other test will give you a pretty good idea of what shape the car and engine is in.
Most of all be comfortable with the car and make sure it fits you well cause youre gonna spend lotta time and money with it so make sure its what you want, plus you dont want your mom to bitch at you when the car breaks down and you have to borrow her car all the time.:thumbup: