I have a piece to read that gives the tempo of dotted quarter = 144. Does that mean it's at a quarter note = 96? The piece has a time signature of 12/8, and I'm guessing each eighth note is played at a rate of 96 bpm. Is this right?
If the dotted quarter is played at 144bpm, that means that 144 of them will fit in a span of one minute. Since there are three eighth notes in a dotted quarter, then there are 144 * 3 = 432 eighth notes that will fit in this same span. And since two eighth notes fit into a quarter note, there are 432 / 2 = 216 quarter notes that fit into this span.
As such, the quarter note tempo would be 216bpm.
A simpler way of finding this tempo would be acknowledging that, since there are three eighth notes in a quarter note, a quarter is 2/3 of a dotted quarter. So we divide 144 by 2/3, which is the same as multiplying by 3/2.
With that said, if the piece is in 12/8, only in rare very circumstances would you use a quarter-note pulse to help you understand the piece. Since the main "beats" of 12/8 are marked in dotted-quarter notes, I strongly recommend sticking with the dotted quarter = 144 recommendation.