Get one of these as well for sure
http://www.rac.co.uk/web/vehiclechecks/status_checks/
my garage provided me with one so it might have one but if not get one done before you go collect it.
The garage ''should'' provide a warrenty but alot of 2nd hand dealers (unless your paying alot) may oly give you a 30 day one or a 3 month one etc so just check up on that - if you bought it and knew a mechanic back home you could get them to check out any faults in the warrenty period then go back to garage to get them fixed.
Check tread on tyres and check for nicks on them (by nicks i mean gauges on the alloys, wheels) as it could be an indication it smacked a curb or something else, also check for uneven wear on the tyres. Depending on the millage check for cam/timing belt changes (can usually be done from about 60-80k iirc) - just ask the garage if there is any proof of this in the service history - recipts etc, if not then assume its not been done and will be about £400 give or take depending on car.
Check oil is not thick and gungey (take out dipstick and check it) hopefully that shuuld be an indication its been changed.
Urm ill have a think what else I check when I went to get mine and post it up but I think that was the main things, like mine I checked the underneath of the oil cap for mayo looking film cause its a common problem on vauxhalls so there may be some common problems to check for on the make you are getting.
Good luck hun oh and DONT forget to test drive it and DONT let the sales man pressure you and remember they will want the sale you are doing them a favour giving them commision!