Aquatic Community: A good starting place with a number of articles on commonly found fish.
The Cichlid Forum: Profiles on nearly all Cichlids, breeding tips, and articles ranging from build your own guides to cookie cutter tank setups. Browse the library and be amazed.
Petshrimp.com: All you ever could possibly want to know about keeping freshwater shrimp.
Other places of interest
Jen's Blog: My wife's blog. A more normal view of our lives, you could say.