I've painted Fenrisian Wolves which are a lot of fun, but I used an airbrush on them. Painting their fur by airbrush makes it much easier for the blending and such.
http://imgur.com/a/Ub3Xz#0
I like the lighter blue colors for the Space Wolves, so I kept with that and added a fade to white on the lower legs for a bit of a "snowy" look to them.
http://imgur.com/a/rsnR3#0
I've also got some
Thunderwolf Cavalry where I used the airbrush again on the fur.
For the fur, I worked with a very light, creamy white for the base white, and then used about four or five shades of grey to build up the levels of fur. The final darkest shade of grey was used for the tops of the wolves and the sides as they went down the legs. For the wash, I used some soft black wash from Secret Weapon Miniatures along with a sepia to get a light shading of brown in between the fur. I finished it up with a light drybrushing of white on the tips of the fur to give some highlight, but I didn't want to add to much so the fur could look a bit natural.