What happened to the Justice League before the events of JLA #10: Rock of Ages?

Question

I've been reading Grant Morrison's JLA, and I'm a bit confused. After 9 issues, the roster suddenly changes without much explanation.

Questions:

• What's up with the blue-faced Superman? How did he change to this version? (In the first page, where the roster is listed, his name comes last, followed by a question mark)
• Why is Wonder Woman not on the team?
• How did Aztek join the team?

It will be immensely helpful if someone could point me to the titles and issues which answer these questions, without posting any spoilers.

Thanks.

EDIT: As pointed out, the Electric Blue Superman appears before the Rock of Ages arc.

Answer 1

• Maybe the digital edition is different, but there's no roll-call in my copy of JLA #10, the "?" you're describing does appear in issue #5 however. Which I raise because electric Blue Superman has been in the title since #5, the American Dreams story arc, and isn't a change in the roster from American Dreams to Rock of Ages. A concise explanation of the Electric Blue era of Superman on Wikipedia.

• Wonder Woman died in her own title, Wonder Woman Volume 2 Issue 125, at the hands of Nekron. Similarly...

• Aztek joined the JLA in his own title, Aztek #10.