Fishdewd - what type of tank do you want? FO,FOWLR, or REEF. If it is reef start by thinking about your lighting. Think about what type of corals you will want to keep and find out the requirements on keeping them. Then move on to filtration. Wet/dry, Rock, Sand, Sand is great becuse of its massive surface area and ability to hold bacteria, my new 90 gal will have a combo of each.
Skimmers you need to do a search on to see what people like, the Berlin classic is a good skimmer, been around a while and preforms well.
Jarvis is right on about the baserock that he got. Those are some very nice calcium cabonate based rocks. One of mine was so big I had to cut it in half, which made great shelfs, got it the same way on ----.
Thomas