If you are going to be installing XP, you can boot from the XP cd & when it gets to the partitioning screen, highlight 'unpartitioned space' and press 'C' to create a partition. This lets you specify the size of the primary partition.
Repeat this process to create the extended partiton with a logical drive to fill the remainder of the disk space.
The other method is to create a win98 boot disk with fdisk on. Boot from this & run fdisk.
Create a primary partition of whatever size you want.
Create an extended partition that takes up the rest of the drive, then create one or more logical drives.
Remember to set the primary partition active & reboot the system.
If you are going to format the drive as FAT32, run 'format c:/s ' when the system has rebooted from the floppy. You can either format the second partition afterwards using 'format d:'
If you are going to install XP & wish to use NTFS, just boot from the XP CD & let it format the partitions for you.