Welcome to the board!! My recommendation is to just read everything you can find. There is a tremendous amount of info here.
I've had my droid for over a year now and been rooted almost a year. I flash roms like a crazy person. Some times 2-3 per day!! I now mostly use Sapphire and Ultimate Droid, but there are some other great roms. You really can't go wrong with any of the popular ones. I tend to now pick which roms I use as "daily drivers" based on which themes are available for which roms. In other words, I pick a "look" that I like and then load the rom for that theme.
Anyway, read and enjoy.
BTW, if you haven't already, create a nandroid backup immediately. In fact, create a backup every few days and definitely before you make any real changes, such as changing roms, kernels, themes etc.
