Strength and Conditioning For BJJ
Here is a great little video on strength and conditioning for Brazilian Jiu-Jitsu by the Juggernaut Strength crew!
The entire purpose of your strength and conditioning program should be to supplement your Jiu-Jitsu training, not replace it. A good strength and conditioning program will help you build a good fitness base and should help with injury prevention.
This video shows a great routine that you can get started with.