Before you start building your system download the following software and system drivers (examples below) :

1. Motherboard update bios & related software programs.
2. Sound Card
3. Printer
4. Webcam
5. Anti-virus
6. Adobe Reader
7. Real Player
8. Quick Time
9. Some Microsoft Update

to Flash Drive/Thumb Drive & this will give you quick access to the software or system drivers so you already have them on hand in case you don't want to hook-up to internet while building you system. It also keep you from load a lots of disks to install these programs and drivers and in case you have a hard disk crash and need to reformat.

This is very informative information about software and drivers. Not only these softwares are enough while building your system, the most important software is remaining which is fire fox.