the best thing to do is go to the library/bookstore and get some good books. I would read Fenner's consciencious marine aquarist, there is also a recent book which i have not read but have heard is very good (cant recall the name, sorry...someone will)...also, remember that a small SW tank is much harder than a small FW...I would personally say you should decide beforehand where you want this tank to go before you get too involved...will this be fish only? fish only with inverts? all out reef?
after you decide what you want to do, find out what you need equipment wise...filtration and lighting needs vary greatly as you move through the spectrum of inhabitants...if you can give us some more info on where exactly this tank will be going many people will chime in with suggestions on equipment, etc
nano-reef is a great resource, for sure read the articles...personally the folks over there are a bit bristley for my taste but they do have good info if you want to get on the BB. I believe, however, between books and people here you can find all the information you will need on most subjects. The most I do on nano-reef anymore is search the posts for a subject