I'm by no means an expert on what you should/should not do here, but the general idea of being a Casual 10 man tank like myself is pretty straight forward:
1) Get to the 540 Defense Cap ASAP, else you can't tank bosses.
2) Concentrate on EH exclusively unless there is a stamina bonus of +9 or better to match the sockets (assuming no more than one non-blue socket). So your gems of choice are Solid X over all else (the +24 is just fine for 10 man normal modes).
3) Leave your Hit/Expertise/Dodge/Parry to your gear, and don't gem for it. There is simply no need at the moment.
Here is the link to my armory: The World of Warcraft Armory
Very boring, bland Prot spec to work with that is used by a good 90% of the Warriors out there.
As a casual tank we can't be caught up in the hype. Hardcores will carry 2-3 sets of gear (EH, Threat, Block, 100% Taunt/Interrupt Guarantees) for different tasks and will often times re-glyph (if they don't already carry two Prot specs, which I'm considering as well) between bosses simply to be more effective at a certain thing (cooldowns, blocking, etc.). Ignore all that. Just use a mainstream boring talent selection like mine, and pretty much any upgrades you get focus on EH and you'll be fine.