1996 Chevrolet Blazer

1st off, I'm a total moron, forgive the lack of detail. That being said, the 96 blazer in question (151k miles) has been having trouble starting. I noticed it started better when it had a full tank of gas. NOW, even though the tank is full, it has trouble starting. Tonights episode had a friend jumping on the front bumper while I cranked it. As I was cranking, I noticed the humming (I assume is the fuel pump) began to sound. Warbled. Like it was shorting out. I have no difficulty hearing the whining hum before the engine turns over, or cranks any other time. I know it needs work, but I'd rather have SOME knowledge as to what the problem is. I replaced the battery as I drained the other one trying to start it. As of now the starter works and the only other symptom is sometimes it feels like the engine sputters a little once I get it onto the freeway. After a few seconds, the acceleration is normal and fine. I have no knowledge of this vehicle and figure I could go broke correcting each of the symptoms. If anyone can help, I would greatly appreciate it.
October 15, 2007.

1st thing 1st get that fuel pressure check with a gauge and report back with the readings then we can move on to other pertinent areas.

Oct 16, 2007.