MGR have a little bit of information on the MG TF on their official website www.mg-rover.com - click on the MG Octagon, then once the page has fully loaded, click on "Development Zone" across the top. I'm suprised it's not featured in a lot greater depth - after all, this car was "officially" launched on 8th Feb!!
Personally though I'd recommend the main site here, www.xpower-mg.com, as the information is far better.
In other words Jerrys' site wipes the floor with any other. Period.