http://www.winaddons.com/
you can download the add-ons to be included in the xp cd you are making!!
it will have, some players, mini apps, codec packs etc.. mostly freeware (eg. vlc player).
http://xable.net/
it has all the high priority updates that appear on windows update. you can read the instruction in the website.
they are self explanatory.
These are optional only, if you don't want , just leave and continue with your own choice