Greetings from Tampa!
1-. Its a great hobby to have.
2. - Do not purchase anything other then books for the first six months. Read everything here on ReefCentral. Its an amazing source of information.
3. - In this six months Look at the Orlando and Tampa Bay Reef Clubs. I would strongly
suggest you attend as many meetings as you can. Nothing in this hobby comes quick or easy. If you want it done right, and last a long time just read non-stop for the next six months.
4. - As far as tank size.
65 gallon 36" x 18" x 24" - extra width to aquascape your live rocks and have room for extras down on the sand bed.
90 gallon 48" x 18" x 24" Same as above but longer tank for fish to swim
120 gallon 48" x 24" x 24" Same as above but even more width if you want to do more rocks if you want to place coral in the tank. Also take note that with a 4' length tank it will stop you from getting some species of fish (ie Tangs)!
5. - Also get a RR (Reef Ready) tank pre-drilled so you can put a sump under your tank to hide all of the equipment you will be researching over the next six months.
6. - This is a hobby where buying something on the cheep may cost you a lot more in the long run. If you buy a $99.00 skimmer and then find out two months later it was a piece of crap you are now buying a $269.00 skimmer to replace it. Research every purchase here before you buy it. Learn from others and it will save you $$$ in the long run.
7. - Visit the following two places.
World Wide Coral -
http://www.worldwidecorals.com/
11765 South Orange Blossom Trail
Orlando, FL 32837
(407) 856-2066
Fish and other Ichthy stuff (FAOIS) -
http://www.ichthythings.com/
105 Fairfield St
Oldsmar, FL 34677
(813) 891-4291
I know both of them are a drive for you but once you visit those two you will be spoiled! The employees are knowledgeable and a great resource for new people.
8. - Research Protein Skimmers and Lights. That will eat up alot of time. Try and get the overall feel the products and try and avoid all of the back and forth that gets you no-where. I would say start with "Lighting, Filtration & Other Equipment" and "New to the Hobby" for starters.
You have taken your first step into a long (and expensive) road but the payoff in the end is so worth it.
Joshua