Discs we use at our company:
1. Bootable CD 1: Windows XP PE Environment with many tools added.
2. Bootable CD 2: Many bootable tools such as partition editors and linux environments.
3. Drivers DVD: Unpacked copies of all the drivers from driverpacks.
4. Drivers CD: Stand Alone Driver disc built with driverpacks.
5. Autopatcher DVD: just in case they are on dialup or some other similar problem.
6. Software disc: kept up to date by ketarin.
7. Bootable: Mac bootable disc, universal, works on both ppc and intel.
8. Service packs CD 1: XP service packs
9. Service packs CD 2: Windows 2000, all office service packs.
10. Service packs CD 3: Windows Server 2003 service packs.
11: Service packs DVD: Vista service packs, both 32bit and 64bit.
12: Combined DVD (for ease of use

Combines the 2 bootable discs (1 and 2,) the software disc 6, and all the service pack cds.
That covers most of what people will need. The bootable cds are built using BCDW.