Well, since shamans are not really a popular class, there's only a few sites...
http://shammy.wikispaces.com/ - not really developped, but has a few nice guides, notably the dualwield, windfury and slow weapon explanation.
http://forums.wow-europe.com/thread.htm ... 1000&sid=1 - overall guide collection
http://forums.wow-europe.com/thread.htm ... 6466&sid=1 - all-tree builds
http://forums.worldofwarcraft.com/threa ... 5539&sid=1 - long shaman macros thread
http://www.wowinsider.com/category/totem-talk/ - wowinsider shaman column. Not always reliable, but I learned a lot from comments.
http://www.wowwiki.com/How_to_kill_a..._%28Shaman%29 - pvp guide - how to kill any class you want
http://www.wowwiki.com/Shaman_instance_grouping_guide - how to play in dungeons
http://wow.curse.com/downloads/details/5723/ - totemus addon, must have for any shaman.
http://wow.incgamers.com/forums/forumdisplay.php?f=71 - quite nice forum, and a good site overally
And some overall helping sites:
http://www.lootables.com/ - great profession leveling guides
http://www.wowreputationcalculator.com/ - shows you your rep, but more important - click on a faction and it'll shouw you what quest you can turn in for rep, what mobs you can kill, what instances run and what items grind. <3
Also, about wowwiki - I find it much better than thottbot, mostly because of valuable user comments, compared to thottbots flames and troll fights. Also it has a brilliant search engine, allowing you to create almost any filter you desire.