Yea, you'll only need the DVD iso. You will be fine as long as you don't format or install FC5 on the Windows partition. Make sure you partition first using gparted before installing FC5. Create another primary partition. Usually if you only have two partition and they are both primaries, depending if you have a IDE hard drive or SCSI/SATA. The partition will read hda for first IDE hard disk and sda for first SCSI/SATA disk, the letters after hd or sd like hdb means second IDE disk or sdb second SCSI/SATA disk.
The partition would look something like this on my machine for example
sda4 Extented Part.
sdb1 Extended Part
sdb5 Backup Part.
That's why you should partition first and not let FC5 do it for you if you don't know what to do it might just overwrite your Windows partition. After you finish partitioning, make sure you can still boot into Windows before you begin the installation.
Heres a step by step for you http://www.stanton-finley.net/fedora...ion_notes.html