Im having trouble fingering the chords D/C, D/B, and D/Bb. Would i finger a regular d chord then use my thumb to the play the C, B, or Bb note? Also im playing these in transistion, any help would be appreciated, thanks.
Play the regular D chord with you first 3 fingers, then use your pinky to dd in the bass notes for the D/C. D/F#, use your thumb cause its easier. For D/B, play the D chord with your middle, ring and pinky finger, and use your index finger for the bass notes.

Hope that helps.

Try just playing a D5 and using either your pinky or index like so

--3-----r                r
--2-----m              i
--0-----        OR    
--3-----i                m

or like


Yeah Dimebag is not the "Greatest Guitarist" of all time... Hendrix maybe... I must go get food to eat with my mouth

$250 for an amp? wow. is it worth it to invest that much in the amp?

Well, I personally wrap my thumb around to catch all of the above mentioned bass notes. You could also just use a D5 and use your free finger to fret the bass notes, although the suggested fingerings by RPotts are very cumbersome, at least in the first example. If you are playing with a bass player then your problem is solved but... if your like me your just playing solo :P. If your thumb can handle it, I would use it.