Pokemondb..net, or pokemon database, is a pokemon vault of information. There, you can get info on things such as pokemon, moves, and abilities without the clutter and mess that many other sites have. It also features a Q & A section where registered users are able to ask questions concerning the game when it might not be covered in their database. The site also has a twitter account from which it posts periodic updates. While one of the lesser known pokemon sites, it still holds up well as a reliable source of information.
Want to know what moves Giratina learns in Pokemon White? Then go to pokemon db to find out.