hi,
we dive that area fairly frequently. hope this gives you some leads to start...
definitely check out the "extended horizons" boat/crew (i think website is the same name, i am sure you can find it in a search engine). clean boat, nice people groups moderately sized and i think i remember seeing at least one DIN tank on the boat - you could probably make arrangement for more. they make mostly runs straight across to lanai and they always take the extra time (and fuel) to go further around to the back side of the island if thats what it takes to find the best conditions (unlike some of the shop boats i've been on). the boat leaves early (because of the trades, like the earlier post mentions) but from mala wharf (about a ten minute drive from where you are staying. you will most likely have to make the _really_ early drive to kihei one morning to catch a boat out to molokini (do it early in the trip before you've adjusted to the time change - makes getting up so early easier). but spend the rest of your 'boat' money on lanai (imho).
good warm up for your buddy team with a simple sloping out and in reef with great public facilities (read freshwater showers) try "airport" beach.
some good shore dives to ask for, for starters.. (ie i would and have gone back multiple times after once with a guide... but there are more spectacular - and harder to get to spots so ask around):
black rock (you're staying right near it) is a great dive _especially_ at night (once you do it once with a guide it's easy to repeat with a buddy). enter from the golf course "back side" and continue on around to the beach side for your exit if air permits (the snorkelers will be so jealous when you come around the bend
the old mala wharf piers (sunken - like a wreck) often with a couple of white tiped reef sharks hanging out underneath - also, if your there right after a storm, check out the bottom for any _old_ beer bottles - some are worth $$ as they were thrown over decades ago when the wharf was still standing.
slaughterhouse (nasty set of stairs to the beach - seems like a hundred +) but have seen pods of dolphins in the bay and a ton of turtles
for the slightly more advanced (because of the 2' rock exit)... scenic point (you literally pull of the road by the tunnel on the highway and hike down - and up- the cliff.) but neat critters because of the steep drop off - always seem to see a new fancy nudibranch on that dive - but you've gotta look hard
. fyi - the exit on this dive is inherently challenging, you should do this dive with a guide.
Off topic, but best vacation"eats" to seek out: hula grill (in the whalers village) - firecraker mahi mahi is the best! maui taco's down the highway (kahana? honokawai? don't remember - but heading that direction) makes a great lunch. pacific fish co. on the main drag in downtown lahaina has the best fresh fish and 'coolers' half a block up from the waterfront on one of the side streets has an eclectic menu (if you like peanuts, try the pasta in peanut sauce - to die for). for a really romantic dinner with the best sunset around, make a reservation (several days or more in advance for the sunset seating) at the plantation restaurant in the clubhouse at the golf course at kapalua (15 min drive from you).
enjoy your trip! hope this helps. (by the way, i don't know if it will be like last year right after 9/11 or if it is just a mini "low season" right before all the travel in and around the holidays, but we were there the two weeks right after thanksgiving and it was like having your own private island).