Online help for an old player returning?

Hey, I am planning on playing the game again after being gone for quite a while. I never played much online, but am starting to consider it. Therefore, I am looking for general advice as to important things to remember against real players, common strategies and stuff like that :)

Also, are any of the gods considered severely over/underpowered? If I remember correctly, I used to play Isis(for the late game), Set(for the fun of having an animal army) and Gaia(don't know tbh) with a little Loki(rush) in the mix :)

Also, if any of you can explain the basics of chinese strategy that would be very nice :) I know how they work, but I really have no idea how to get the most out of the things they have xD