Lots of documentation can be found in your /usr/share/doc/ directory as well. Anyways, here are some pointers to help you on your way.
1) Not sure about what settings may be in place for expired user accounts. At any rate you can always re-create the account. As root try the adduser command from a terminal, it should guide you through creating an account. If it doesn't then try the useradd alternative. The fstab file is strictly for mounting volumes (cdroms, hard drives, etc).
2) As far as mounting FAT and NTFS partitions go you've got some things to consider. First, NTFS read-support in the linux kernel is still experimental, as is write-support; support for FAT partitions is fully supported. If you don't want to risk anything you can do what I've done: set aside a separate FAT partition for things like mp3s, documents, videos, etc, while keeping the windows OS on its own partition (or simply install windows on a FAT partition).
Here's a samples from my own /etc/fstab:
/dev/hda1 /mnt/win2k vfat uid=500 0 0
/dev/hda5 /storage vfat user,uid=500 0 0
My partitioning scheme has windows 2000 installed on the first partion of the first hard drive (hda1). It gets mounted in /mnt/win2k. It is of the type vfat (a FAT32 partition). The next option states that the user who has the ID of 500 is the one who has permission to read and write to it. Keep this in mind: FAT partitions do not recognize multi-user permissions. Only one user is considered to have such permissions. In my example, I'm the only one who uses this workstation, so I've given my own account (having a uid of 500) read/write permissions. Note the second entry; this is another partition which I've set up strictly for storage (mp3s included). Unfortunately, if several people share that machine you'll have to devise another method sharing mp3s with them.
XMMS is a popular program for playing mp3s, but Redhat have decided (wisely, IMHO) to remove all software not strictly open source which includes support for the mp3 format. You can find an xmms mp3 plugin at
http://freshrpms.net.
3) Wish I could give you more pointers on LILO, but if you peek inside /usr/share/doc/lilo-21.4.4/ you'll find all kinds of documention. Like the previous poster I prefer to use GRUB as well. At any rate, writing to the Master Boot Record should be fine. Though I'm kind of surprised that LILO even got installed, I thought GRUB was the new default boot loader in Redhat (shrug).
Well, hope some of this helps :-)