Here are a couple of great tutorials on wells and pumps....and there are others.
Check with the former owners. Check with your Health Department to see what they may have in their permit records for your well, if anything. Check with local area well drillers, plumbers, etc. to see if they installed the last well or know anything about it. You might even check with your School District maintenance people to see if they may know anything.
I would hav eit all inspected in any case.