Hi smooth,
I am sure you will not make any mistakes, you will be just in need of a few points. One word of advice buy live rock. It is expensive but pays off right from the start. It will help prevent you from having an algae bloom or from having to deal with high nitrates and keep your tank stable right from the start. Also set up a refugium, the largest one you have room for in conjunction with your sump. last get the largest Skimmer you can afford. If you can't afford much look at buying a used one. I just purchased a used AquaC EV240 for a good price and I have an ASM G4X set up. I highly recommend the
ASM's with the recalculation modification. and the price is reasonable next to the other high quality skimmers which tend to go for an unreasonably high price > $500. You can't over skim. Yes It can remove trace elements and other things but that can be replaced on a regular schedule. Water quality is more important. Plumbing is an other thing you might have questions on. Check out Dans' thread "GoldStripe". He just set up a 150 "My 150 reef photo Journal". Well, Happy ReefKeeping and hope to see you tonight at the meeting.
Patrick