Niantic Labs are the creators of the Pokémon GO app, and they have a subsection of their site dedicated to it. Here you can see some cool updates about the app itself, like it being released in other countries! You can also submit a support request or look through the FAQs.
There is lots of good info on the official Pokémon GO website: http://www.pokemongo.com/ You can find out about all sorts of stuff in the game and get some good, high-level info. It’s also the first place to have the trailer (aside from YouTube):