Tale of Painters is a good one, loads of cool stuff, plenty of
WIP and finished work and a bunch of tutorials:
http://taleofpainters.blogspot.co.uk/
Light Miniatures is good too, he's not posted a huge number of actual tutorials but always goes into great detail about his methods and general approach, if nothing else you'll get to see some absolutely stunning minis there.
http://www.lightminiatures.com/
Finally, I'd be remiss not to mention Warhammer TV on Youtube/Facebook, loads of really nice, professionally produced tutorials from the mighty Duncan:
https://www.youtube.com/user/GamesWorkshopWNT