You roll at the beginning of your turn, and at the end of your turn if it did not wake up the first time.(When it's going to be your opponents turn).
You are allowed to add energy to the pokemon, but it is still asleep.
As for evolving you can also evolve and that makes the pokemon wake up so for example:
I have a sleeping Gabite on my field, and a Garchomp in my hand,
I place the Garchomp on top of gabite to evolve and now you are awake and can attack.