It’s impossible to cover all the good sources of cichlid information but here is some good ones I have used.
http://www.cichlidresearch.com/ This is a site put up by Ron Coleman. It is more on the scientific side of cichlids if your interest tends in that direction. I find him interesting.
If you are more interested in the practical keeping and raising dwarf cichlid’s then this site is for you; http://dwarfcichlid.com/Apistogramma_cacatuoides.php