I usually just google the symptoms and see what I find. There are a number of really good websites I read through that helped out with the clutch problem we had last fall. They had diagrams and explained things pretty clearly. Unfortunately, I do not have those sites bookmarked or anything so I cannot figure out what I used. This one is the only one I remember:
http://www.edmunds.com/ownership/techcenter/articles/43837/article.html
and I did not find it by putting in the symptoms (clutch wouldn't engage) but found it after I had found the key words "clutch bearing".