What's a service consist of?

[Curt]

It depends what level of service it requires. But if you don't have any history for the car, you'll probably want:

Oil & filter
Fuel filter
Air filter (unless you have a cone, of course)
Spark plugs
Cambelt kit
Water pump
Possibly coolant/thermostat change
Possibly brake fluid change
Possibly gear oil

Cambelt adds a fair amount to the bill, especially if you're paying someone. But if you have no idea when it was last changed, then it something to think about.

Then everything else you should give a once over, brakes and suspension etc.