Favorite class guides out there?

Seconded on icy veins.

Maintankadin is always pretty good, but as the name suggests, it's pretty narrowly focused. Discussion on other classes/specs is well-informed but purely secondary.

Healing seems spotty at the moment. Elitist Jerks seems hit-and-miss. Plusheal is still around but discussion is even deader than here.

A lot of the classic blogs have died for various reasons or get updated very rarely.