well, first of all check out
http://www.mpc-forums.com. lotsa MPC related stuff.
in terms of tricks for sequencing check out track mutes. totally awesome for playing live. that to me is the key of playing a sequence "live" with the mpc.
try sampling notes or phrases from your hardware and playing it in "16 Level" mode adjusting pitch or velocity. you can come up with creative stuff when playing melodies percusively.
use the mpc as a midi controller for your mnm. sorta like 16 Level but in the midi realm so you have more control. i do this a sometimes for bass lines or submelodies.
sampe drum hits from your md into the mpc and bang stuff out. i usually sample drum loops and use those for play back but i often will sample all the one-shots from the kit i used to program the pattern and then build an mpc program with it so that i can play along live by banging on the pads and the drums sounds feel appropriate.
get familiar with the Note Repeat / Tap Tempo button. be careful not to inadverantly change the tempo but note repeat is fun (especially in 16 Level mode)
assign the sliders to samples you've sequenced so that you can sweep on a filter or something.
none of those are tricks per se, but all handy features that i use daily.
have fun!
I'll let you know how it works for me.
