I'm laying down some guitar tracks and want to be able to add some drum tracks as well but I want to be able to change the speed of the tracks to fit my guitar parts. It seems all i can do know is drag a drum loop into a track and that is it. Am I missing something? thanks

I would upgrade to Guitar tracks Pro and buy Ezdrummer and there are lots of add on kits for it.
 
 
 
 
 
 
 
http://www.toontrack.com/products.asp?item=7

I am just learning about loops but I tested this and it seems to work.  Find a drum loop that you want to use and put it in a track. Highlight it and then down at the bottom of the screen where it says beat|tempo you will see the tempo that the loop is presently set at.  Click on the number and it will highlight with a +/- sign.  You can either adjust the tempo using these signs or simply type in the tempo that you want. 
 
EZ Drummer is a good drum kit but it is another piece of software to learn.  I personally would play with the loops first to see if they meet your needs.  Cakewalk also has Session Drummer which you could look into. 
 
Hope this helps.
 
4partmusic

ez drummer is very easy to use.
but session drummer is easier as far as writing parts.

this comes with guitar tracks I believe, its called cakewalk studio drums:
http://www.youtube.com/watch?v=k83UVo1OiKA

this is basic midi videos I made.
I have 3 check out my channel to see the rest.