Clematis

The clematis in the backyard this year is FINALLY growing into the shape I've been training it to.  The eventual goal is to have them grow onto the large tree trunk that's along the fence and covered by the beautiful purple flowers and foliage.  

I never know how to prune back clematis during the off season (Fall?  or Spring?).  So I did a little bit of research on the "inter-web" and found some useful links:

http://www.raymondevisonclematis.com/main/guidesPruning-simple.asp?a=1

http://www.finegardening.com/how-to/articles/clematis-pruning-guide.aspx

Also, I've been trying to figure out what kind of clematis this is as it was planted by the previous owners of the house.  After some research, I think this is the common "Clematis Jackmanii" - purple in colour and four-petal configuration.