[Valo's Moirana]

i have 55gal tropical freshwater tank which is overpopulated by an albino oscar, chichlids and a large pleco (adopted the tank from the previous owner)

i also have a 10gal freshwater tank for my grandpa-goldfish elmo (who btw is the coolest fish in the world *proud*)



to begin, really any starter book is useful which can be found in bookstores... that helps to figure out how to (properly, not like mine) set up the tank, start up period, which fish to get, how to populate etc.
once you're through that type of book, you can find advanced books, online forums (there's one just like BB for fish in general as well as for oscars, PM me if you'd like the link) and magazines.