Clunking and Humming Noise

I have a 2005 Chevrolet Blazer.  It has recently began  making a humming noise when i accelerate, it also pulls to the right when I drive, intermitantly though.  When I brake for a while sometimes it stops pulling. I am am replacing the tires in a few days, so i figured i'd get everything done to it while i'm waiting and then drop it off for the tires, they are like 2/32'nds.  I figure that it may be the pads/rotors doing the pulling.  But I was told it could be idler arm and The front Wheel Bearing hub assembly.  What about front end ball joints how can I tell if they need to be replaced also.  What else should i be looking at.   I am thinking this baby needs a front end overhaul basically.  I don't wanna take it to the shop, for anything but the tires.  I have a garage and access to the tools.  HELP! 

I'd say idler arm. I belive that this is the arm that isn't connected to the steering box. It is the one on the passenger side. Today I was told otherwise by a parts guy at the local shop!!!..............weirdo! The one on the steering box is a pitman arm.