in re your printer problems, it would help if you told us what priner(s) you use. The CUPS (common unix print system) that you installed with Ubuntu may have drivers. You just need to set up CUPS to use your printer(s).
Open a browser. In the URL field, enter this URL: http://localhost:631
. That will get you into the CUPS management apps. Click on *Add Printer* and go through the steps.
For installing XP along with Ubuntu, you will have to repartition your hard drive to add a partition to install XP into. Use your Ubuntu instal cd as a liveCD. Use application gparted to repartiton your drive (the partition you have now must not be mounted when you try to repartition). Make a partition behind Ubuntu for your XP installation.
Then shutdown and restart with the XP installation cd in the drive. Install XP in the new partition.
NOTE: XP will write it's own bootloader to the MBR of the hard drive and you won't be able to boot Ubuntu. Search these boards for Linux/XP dual boot issues and how to re-instal grub to the MBR, and what edits to make to /boot/grub/menu.lst so that you can boot both Linux and XP.