I personally would never use the EQ in the MPC for anything surgical or for sound shaping.
Pick the right samples from the gate and just make the beat. After that, track it out into your DAW where you can use better EQ's/filters.
For kicks, and every kick is different, the "THUMP" usually sits between 40 and 100Hz. The "body" can lay anywhere from 200 up to 800Hz. Boosting 500Hz usually results in a "boxy" sound... so 500 usually isn't a bad area to make a cut (works on vox also)... 800 - 2K is usually the beater or snap of the kick. Like mentioned earlier though, if you pick the right samples off the bat, your EQ'ing should be minimal... Unless you're working with.... BASS
Bass is normally compressed. Depending on whether your using a synth or live bass, bass usually has a LPF... try a 12db slope and twist that knob until it sounds right. I like to EQ the bass depending on its relationship with the kick. If the kick is sitting under the bass and I'm boosting 80 on the kick, I'll dip 80 out of the bass to make room for the kick and vice versa. Bass tends to live in the low mids... but be careful about getting it muddy!
Another way to EQ is to boost a small notch and sweep the frequencies... once you hear something offensive, bring it back and cut a bit... The better you get at EQ'ing, the more you find yourself cutting and the less your find yourself boosting.
Good luck.