Since there are no official guides for Pokémon Go, it's become somewhat of a black art and it's up to avid players to share their knowledge. Here you are - my small contribution...
Welcome to Pokemon Go Evolution Chart! Now with Generation 2 Pokemon Evolutions! As you play Pokemon Go, you might be interested what stages are various Pokemon evolve through. For the most part, you'll be catching Pokemon in the wild at stage one. Some Pokemon cannot evolve, some other can evolve once, while the rest can evolve twice. Some pokemons are multi-evoluted like Gen 2 Tyrogue and Gen 1 Slowpoke and Eevee (that has 3 evolutions in Gen 1 and one more in Gen 2 with Espeon). Take note of the candy costs to evolve Pokemon from stage to stage.
