I think you're pretty much on the right track. The three main equipment that you should have for a reef tank are high quality & quality lights, a good skimmer, and live rock & sand. There's other methods that people use for filtration, but if sticking with those three can't do you any wrong. A fourth equipment that is HIGHLY recommended is a Reverse Osmosis freshwater filter (makes water for you to mix saltwater and top off evaporated water with).
For a 75 gallon, I highly recommend getting metal halides, either 2x175 or 2x250 with fluorescent supplementation. If you don't have a canopy, you can get a pendant halide system. If you do have a regular canopy, you're either going to have to build a new one to house the halides (which require 12" or so of clearance to mount) or you can go with power compacts or T-5 fluorsecents instead. But halides is definitely the way to go if you listen to the experiences here.
As for the skimmer, there are a lot of choices and it depends on if you want to go with a sump or not. Going without a sump is simplier, but sumps have a lot of benefits that is worth considering. Let us know what you'd like to do. There are several pretty good hang-on skimmers that can do alright for a 75 gallon if you don't want to install a sump. But if you do, there are literally hundreds of other skimmers to choose from.
For your tank, 80-150 lbs of live rock will do well for your biological filtration and be a nice habitat for your corals, fish, and other organisms. I personally recommend going with a 3-5" deep sandbed which will add addtional biological filtration (nitrification and denitrition) as well as more habitat for burrowing microorganisms. The idea is to provide as much and as diverse a biome as possible so you can have as much and as diverse a population as possible.
Most photosynthetic soft corals are great beginner corals, as well as polyps and mushrooms. Large polyp stony corasl (aka hard corals or LPS) are usually pretty good choices too. The two LPS to avoid are Goniopora (aka Flowerpot) and Elegance corals. Inverts that are harder to keep are Small Polyped Stony (SPS) corals, sponges, anemones, and filter feeding worms (e.g. Feather dusters). These are more fragile and should be kept after you have some experience and are able to provide adequete care for them.
There are MANY good fish to pick from
Most damsels/clowns and gobies make excellent beginner fish. There are some hardy wrasses that are reef-safe, along with basslets grammas, cardinalfish, and blennies. Dwarf angels are relatively hardy, but some like to pick at corals. There's really too many to list, so the best recommendation I can give you is to find fish you like and come back here to ask if they're ok for your tank.
This is a terrific hobby that I think you'll get addicted to. Welcome to reefkeeping!
