Can anyone give me an answer to the following? -Which OS can best be installed first, CentOS or XP? -Are there special actions required to enable proper dual booting? -Which boot manager can be used best CentOS' one or XP's one?
I strongly recommend you to install Windows and Linux independently on separate disks. The trick is to make Windows believe that it is sitting on the master drive, while it indeed is on the slave :-). See http://www.bioxray.dk/~mok/dual-boot.html for a more detailed description!
There are many advantages to this approach, most importantly you can always change the setup without having to repartition *shudder*.
Cheers, Morten