You can't be that new, at least you know that you have to "mount" them
The general format of a mount command is:
mount -t <filesystem type> /dev/xxx /mnt/xxx
where /dev/xxx is the device file and /mnt/xxx is where it will be accessed, aka, the mount point.
That's how you mount things manually.
Check out /etc/fstab which is your "filesystem table"... This is where you will add entries to your cdrom drive and permanent partitions to be mounted on boot. Once you have the correct entry there, you can mount with a simple "mount /mnt/dos" or by clicking on an icon if you have that setup within kde or gnome.
winXP uses ntfs by default, which is readable by linux but not currently writable. fat32, which win98 uses is read/write in linux.
as an example:
mount -t vfat /dev/hda3 /mnt/win98
would mount your third partition using fat32 to /mnt/win98.
you can use
cat /proc/filesystems to get a list of filesystems currently supported by your running kernel.
--Shade