Mike,
I just started my first Salt Water Tank.
I walked into ***** to by a fresh water tank and found my self buying Salt water equipment.
I found out that there is alot more maintenance involved and that time and patiants is vey important. Don't be discouraged, for you will need confidence and high hopes to develope your little eco system.
I personally own a 30g tank and thought that it might be to small. It seems to be going well. I started with a basic water fall filter system and heater. I then filled it with about three inches of crushed shells. Waited about three weeks before added about a pound of live rock per gallon. Another four weeks to establish algea and stability.
I imaging that I might have jumped into it, but I learned alot from my guys at my local aquarium and from asking alot of questions when I could i was able to understand more as I went on.
Summary:
Do it, but don't rush it.
Have fun with it, and enjoy.
Best of luck!
Milo