Check your throne height and positioning in relation to your snare to ensure you are not over reaching and have to found the spot where you are most relaxed and can play the feet the easiest.
Take things slowly, as suggested work on playing the two pedals together and slowly build up tempo. It's a co ordination thing and takes a lot of practice to get used to. when you have the feet working , then add in the hand parts.
One thing at a time, a great book that shows how to practice and i can recommend the concept which helps to set goals,focus, and improve, is Mike Manginini's
Rhythm Knowledge books available from his web site.
http://www.mikemangini.com/