+1 on Greg.
if it tries once, but then just clicks, and the dash lights all go dim, its because the starter took all the juice outta the battery. Well not exactly, it took what it could thru a weak connection and overloaded it.
Pull off both connections, make sure they are clean, flat and can make good connection, then re tighten them up nice and snug.
That kind of car has a fairly old fashioned battery post design so its simple and easy to see, plus its pretty robust.
Check the other end of the ground wire and positive wire too.
Attach a test light to the small power terminal on the starter(and grounded on the other end) and have someone try to crank it. If it lights up while they are in the crank position, everything from the key to the starter is good, you can eliminate that.
If it still tries to crank, its either the power cable, the ground cable(main, big ones) or the starter itself. you can run your own power and ground cables if you want to to eliminate those.