I was so nervous about washing my woollies. I have no idea why I was so concerned, but found in my searching that a lot of people felt the same way. Wool can felt if you use water that is too hot or of course if you put it through the dryer, and cold water can shock the wool. You shouldn't wring or twist as the fibers which are meant to be rough and crimped which is what causes them to stick to each other and form an insulating mesh.
I watched this video from Green Mountain Diapers several times, and finally bit the bullet, and of course it went fine. I like this video because it shows you pretty much what everyone says to do. Some wool can be machine washed, but I plan not to even go there, as it's quick and easy in the sink and I'd rather be safe than sorry.
The video is how to lanolize wool, but the process for washing is the same, you just use the wool wash and make sure it's tepid before putting the wool in. I still start with a little hot water to mix in the wash as it is enriched with lanolin.
Turns out, it's really not so bad. Quite easy. Easier than machine washing!!