I read the guide, basically answered all my questions
The pack came today, I soldered a deans connector on and gave it a balance charge.
It's amazing how if you use a fully charged NiMH pack the wheels spin at one speed. If you then connect the LiPo Pack (which the charger said has about the same voltage) it's like it's been turbo charged! Really didn't think it would make that much difference but it must be the fact there is no voltage drop when you put the power on.
Cheers for the advice all... Need some more LiPos now!