Back to wow, left before Pandaria. Any resource to guide me through all the changes?

Hey /r/wow ! My wife wanted to start playing again, so I'm following her. I stopped after clearing Cata, never looked back, so I'm really out of the loop. I've always played a warrior tank as a main, but I don't even remember the names of the theorycrafting forums I used (and I don't think my old excel spreadsheet would work anymore)

Any advice for an old bloke looking for a quick reintroduction to the game?

Thanks in advance!