Trying to die in reverse

1999 GTZ...Lately when I get in my car, put it in reverse, and let off the brake, it shutters like it wants to die. If I reapply the brake and wait a second it doesn't do it, but I was wondering if anyone else has had this problem? Also, it's beginning to shake a bit when I come to a stop. I know that is the one shining criticism about our car (bad brakes), but I'm not exactly rolling in dough right now, and was wondering if anyone knows of good pads and/or rotors that are inexpensive. Thanks for your help.

verify your trans fluid is at its proper level.
if it is, clean your throttle body.

does anyone have a tutorial or something on how to do this throttle body cleaning