I'm getting started on a reef tank as well, and here is what my (thankfully very knowledgable) LFS told me to start with:
Any Zoos
Star Polyps
Leather
Hammer Coral
Green Brain
Mushrooms
From what I understand, you can have pretty much whatever you want under MH's (as long as the wattage matches the size/depth of the tank), but things like Clams and Anemones I've been told to wait on for several months until the tank is well established. When you're looking, also make sure to look at what their water flow requirements as well as supplemental feeding - some corals need to be fed things other than just light.
I'd also advise posting something in either the reef or newbie section - I can't tell you how much good advice I've gotten from these people!!!
Once you've added things, upload some pics so we can see your progress & look at your already cool looking tank!