If you have a male betta make sure your guppies tail colour is different colour to the betta. The betta wont like it and nip the tail. The tail will grow back but it takes abit of time. Welcome to the hobby!!
dwarfgourami- Thanks for the heads up, I've been keeping my eye out (I'll be going to my 4th LFS tomorrow). Your comment on the guppies was actually part of the reason I like endlers. The last thing I need is sick fish.
Rillan- Thanks for the tip and the warm welcome! I've already moved Darby to his own 3g tank after he decided to eat my mystery snail's antenna.