Having played rugby for a couple of years myself I recommend following scooby's workout programs. They will give you the strong body you need for an intense contact sport like rugby.
http://scoobysworkshop.com/home-workout-plans/Running & jump rope is the way to go for cardio.
I've had the honor to be trained by 2 guys from the NZ All Blacks for a couple of weeks. They literally made us do 100's of push ups every training. This one guys leg was about the size of my chest -.-
We've also been on a rugby tour to England and had a training from the trainers and players from the first team at Bath Rugby.
Pretty unique experiences!
