Yes, it is possible.
First decide how much space you want to allot to each OS. Create two partitions - one for 98SE and one for XP. Don't create one for RedHat just yet - just make sure you leave enough free space on your partition table to be able to create another new partition.
Then install 98SE as you normally would on the first partition, XP on the second partition. The NT bootloader will overwrite the 98SE one, giving you an option to boot into XP or 98SE at startup.
Once that's done, boot from your RedHat CD, and somewhere during the setup, you should be presented with the option to create new partitions for RedHat. Create the ext3 and swap partitions in the free space that was remaining on your partition table. This time LILO/GRUB (the linux bootloaders) will overwrite the NT bootloader, giving you the option to start 98SE, XP, or Linux when you boot up.
Jan, the best thing to do would be to give a couple of the major distros a shot, and see which one you personally like the most. Different people look for different features. Some might be looking for ease of use, some might be looking for the best UI, some might be looking for package management and upgradability. It just depends on what you want. After all, they're all linux under the hood. Just give them a shot, and see which one you feel most comfortable with. Don't bother what other people say and think.
Ep, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS