My 2 cents
Welcome glin7! I have been on this forum a little over a month and have found it to be extremely helpful! :exclaim: You will find no better place! I wish I would have found it about 2 months earlier, right before I got started. I wasted a lot of money on stupid items and lost some beautiful fishes.
Now for my 2 cents. Invest in a quaratine tank to save you lots of headaches and expensive fish losses. Fishes should be quarantined 3-6 weeks before you introduce them into your main display. If not, you risk bringing ICH (white spots / parasites) and other problems into your tank which are near impossible to treat in your display tank without harming other things. Research the fishes before you buy them! Some fishes do not mix well with smaller aquariums, and some are extremely difficult to raise. I unfortunately lost a beautiful 7-inch Powder Blue Tang ($75) after only 3 weeks. He was gorgeous! My setup and experience was not ready for such a delicate fish. Also, don't waste your money on wet/dry or BIO filters. They will accumulate nitrates which are very bad for corals and to fish a certain degree.
As the previous users suggested, do lots and lots of reading and come up with a general game plan. It will save you money and headaches in the long run. I would highly recommend the following books which you should be able to find second hand:
The Conscientious Marine Aquarist by Robert Fenner
Aquarium Corals Selection, Husbandry, and Natural History by Eric Borneman
I would suggest buying a lot of your equipment online as it is quite a bit cheaper than at your LFS (local fish store). However, I believe in buying my fish locally at my LFS as I am still new to the hobby and do not have enough skill and faith in myself to try mail-order fishes. Invest in live rock and a good protein skimmer. I just recently got in 2- Seio 1500 Powerheads ($60/ea) for my 90 gallon aquarium which caused a sand storm, too much power! I would recommend 1- Seio 1100 Powerhead ($55/ea.) or a Tunze Turbelle NanoStream 6025 Powerhead ($62/ea) for your 75 gallon aquarium. That should get you start as far as waterflow is concerned. Plus you will not be wasting any money since they will carry over once you become more advanced. Many advanced aquarist use them. Also, get a portable refractometer to measure your salinity / specific gravity. Those plastic swingarm hydrometers are not always accurate. I would suggest a Visi-Therm Stealth 250 watt Heater or any other non-glass heater. There is nothing worse than a glass heater shattering in your beautiful tank.
![Eek! :eek: :eek:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
And lastly, consider purchasing a Pinpoint pH monitor to accurately measure your pH. It makes life much easier to see a hard number as opposed to trying to decifer what color the test kit came back at and comparing to a faded chart! I have found in my reading over the past month that the Salifert test kits are highly recommended on this forum due to their high reliability which can't be said for all kits. No sense in trying to fix an incorrectly diagnosed problem based on a bad test kit.
Best of luck to you! And I'll see you around!
-Dennis