These are what I use to make teams and find out all of the answers to any question you could possibly
ask-well almost
Pokemon Forever G/S A Site that has info on who can breed with whom. How long eggs take to hatch and
how to make your eevee happy enough to evolve. Also breeding for shinies and how to get a shiny ditto.
Team PA Most of their stuff has been translated from the japanese version so if you don't know the japanese
names don't bother.
Nescrosaro's Pokemon Page Site that has a G/S Pokedex and lists what moves pokemon learn by level. As well as a stat Ranking
The Pokemasters Site that has all the info you could possibly want! Lists of compatible TMs max stats
pokemon locations everything. Perhaps because of this their server tend to be slow so be patient. Make sure you click under the related links heading up in the upper right hand corner
That's where most of the good stuff is.