Sound Deadening

I have a 1998 4dr Chevy Blazer. It rattles a lot and i wanted to put deaden it to stop this noise and so I can hear my stereo clearer. I don't know a thing about sound deadening. So I wanted to know about how much of it I would need for my truck and what kind would be best. Also, can it go inside the dash aswell because I get a lot of noise from there too. And my last question is how much would it cost to buy it and have someone put it in for me? Thanks a lot for your help.

Go to secondskinaudio.com
Call the number under contacts, talk to Ant, he's the owner, and he makes the best deadening porducts I've ever used.
He can answer all of your questions, except how much for the install...