1994 Chevy Blazer is it a dead duck?

Hello,

We are trying to get my brother's blazer up and running. It has been sitting for about 2 years
now, and it won't start. Can you give any suggestions
on where to begin with this vehicle? It tries to turn
over, but just doesn't quite get there. Any help
would be greatly appreciated. We replaced the
battery, and put a fuel additive in the tank and new
gas. -Short on $$, are willing to try to do this ourselves.