My '92 blazer 4wd 4dr has a humming sound that i hear usually only when i begin to accelerate and continues usually until i excede probably 20-30 mph. It also sounds like it may only be on the driver side of the truck that the noise is coming from. Any ideas as to what may be causing this noise???

 

Is it louder on a right turn?
Possible front wheel bearing, left side front.

 

I agree, it is probably the wheel bearing. You should check it out asap because the longer you wait the harder it is to remove and you might end up replacing your entire hub assembly.