I am currently temping out my shaman, and have heard so many different pieces of information that Id like to try to get the correct information.

Soo what does + to aug do for a shaman?

Helps your baseline buffs get lesser variance, and it is maxed out at the level of your highest base buff (base dex, 48), meaning that even if you go higher you won't squeeze more dex points.

So, to get the max dex out of your baseline dex buff:
Are you a classic rvr spec 46aug 27cave? you need +2aug on your items, or RR3
Are you a pve spec 47aug 26 mend? you need +1 aug on your items, or RR2
Are you a cave sham, 32aug whatever else? you need +11 aug and RR6
...and so on...

Oh, same goes for healer, of course.