I used to work at a jaguar specialist before moving to the classic car trade, iv worked on all years of jags, s types suffer from terrible electrical problems due to faulty looms on the bumper, removing a side light involves removing the bumper pretty much, as for tools, get some good bolts extractors, and a torx t47 for the wheel wells, also get a real good dmm you won't regret this one, there's also some speciality sockets but the dealership will have them I would have thought, also on the new xf's the caliper bolt is a 9mm hex bit, buy the gold snap on socket in 3/8 you will need it, also on the aluminium bodied cars they suffer from earthing problems due to the bolts holding the wires to ground breaking in the inner wheel wells, so if one half of the cars electrical fail that will most likely be it, also rust! Lots of it and get used to it, the x type suffers really bad also on the subject of the x type diesels the injectors go all the time! Also get to know your air con systems they always leak on jags, also on s types doing the spark plugs is a real pain the the *** on the v6 and 8 models so have a good array of extensions and be really careful tightening them down, Also jaguar love to thread steel bolts into aluminium so watch out for stuck bolts, other than that have fun shoot me a pm if you want any more information good luck!
Merb