Best forum for the xk is the xk enthusiasts club otherwise known as XKEC, they deal specifically with the one platform, £20 to sign up for full forum access or £45 I think for full membership with quarterly mag and access to the mag achieve and other useful stuff. I just have the frump only version.
Well worth getting a copy of JTIS, its the software used by jag mechanics for all jobs. Its like the pro version of the Haynes manual, but more detailed. You can download for free I think, can't remember where I got mine from.
glad you got one, great cars, and parts are surprisingly cheap, good selection of 2nd hand parts, especially from jagslag on the xkec. And paragon design are worth a browse for custom parts.