I got some Faber-Castell watercolor pencils for Christmas. I haven't done much with them except for a little doodle here and there, but they sure are handy when wanting to add a little color to a sketch (especially when you want to give it a watercolor feel.)
These work really well on 100% Inkjet paper (stay away from Laserjet or any kind of hybrid/general purpose paper -the paper soaks in the water and doesn't let you spread the color around). This particular brand is Hammermill.
I used a refillable water brush to spread the color around. Linework is China marker.