The majorirty here are correct.
5-10 minute warm up cardio, followed by your weight program, followed by 30-40 minutes of good old fashioned fat-burning cardio.
It normally takes your body between 20 and 30 minutes at it's target heart rate to start effectively burning fat. However, it starts doing so MUCH faster if you've been lifting weights. Only 15-20 minutes until your body really starts burning fat, or so I've been told by trainers.
Also, if you're interested in gaining lots of mass fast, cut back a bit on the frequency, impact level and duration of your cardio. Don't stop doing cardio altogether, just trim it back some. I noticed some significant strength and size gains when I cut my running mileage back from 5 miles, 4 days a week, to 3 miles 3 days a week plus a 30 minute elliptical workout. The trainer at my gym advises me to stop running altogether and do the elliptical exclusively to gain more mass, but I don't want to do that. I like running because I can do it anywhere, and therefore have no excuse when traveling.