Wont turn over

I need help! I have just started my 1994 Aspire after 2 1/2 years. We had it running for a couple of hours and drove it around the for a bit; then shut it off. The battery was dead so we changed it but now it wont even start. We checked the battery posts and spark plugs but when we try and jump start it there is nothing. It wont make a sound. Anyone have any ideas?

I would look for a bad cable or connection between the negative side of the battery running to the 'ground' - the engine block or the body. Then also, look at the positive cable to see if there is corrosion or a frayed spot. The insulation can be intact - but with the copper strands inside being dissolved by corrosion or flexing.
Also, a 94 car would doubtless have a set of fuses & relays under the hood somewhere, as well as the fuses under the dashboard. The ones under the hood are the more important ones. There may be a 'main' fuse that is bad, or whose contacts are corroded - just from sitting. There may be a starter relay that is ignoring you. If you can figure out which one it is, pull it out and whack at against a curb or something solid to free up a stuck armature - then try it again.
A good check of the wiring is to turn on the headlights (does this require the ignition to be on? Then you Know there is a fuse and relay box under the hood) and see if they are bright. If not - you probably wont have good current going to the starter either. And the car should start with the headlights being on. If they dont, either the battery is really feeble, or you still have a weak wiring point somewhere.

Sometimes to find all of the battery cables for the negative side, you have to pull the battery out and unbolt the battery box to look underneath.