My Dell Inspiron 8600 (1500 MHz, 512 MB, 60 GB) came with WinXP Home. I've reduced the C drive to ~20 GB and created 2 new empty ~20 GB partitions (1 with FAT32, aka VFAT, and 1 with ext3) using Partition Magic. I want the big VFAT partition to share data files between WinXP and Linux. Here are three (undoubtedly trivial) Qs:
1) Using DDruid I deleted the new ext3 partition and defined *one and only one* new partition, either root or boot (ext3). When I try to define a second I get a message that no primary partition is available, partition cannot be created. The partitions in the table at this point are as follows: hda1, 32 MB, Dell diagnostics; hda2, C drive (NTFS); hda3, tiny (free); hda4, boot or root (ext3); hda5, VFAT. Why can't I create another partition? (What does the message mean? Does it result because DDruid wants to name the next partition hda5, but that number is already taken? Is this problem a result of keeping the C drive on NTFS?)
2) The pulldown menus don't tell me how to define a swap partion. What should the name be? What should the mount point be? What should the file system be?
3) The pulldowns do list /shr, /home, and other partition options. The Installation manual doesn't say what they're for, though lots of Howtos mention them. Do I want them? If so, what parameters should I give them?

1-Are you only using extended partitions or primary partitions? There are limits to each.

2-The swap partition is in the same drop-down as the ext3 filesystem type.

3-For a home system, just make a /boot of 100 MB and a / for the rest, then read on.

Thanks for your prompt reply, ugob. Yes, the swap info is on the FS pulldown. I don't know how I missed it before.

It seems that my conjecture about partition numbers may have
been on the mark. I reran PartitionMagic and made the second and
third big partitions identical (VFAT). Then I ran the RH9 Installation
program. After I deleted the *higher-numbered* partition (hda5)
it was a routine matter to create boot (100 MB), swap (1 GB), and
root (~17 GB) partitions using DDruid. They received logical device
designations hda6, hda8, and hda7, respectively, and now hda5 is
"extended" (whatever that means). So that takes care of Q1 and
Q2.

As for Q3, I think I understand now why /home partitions are used.
It seems to me that my "shared" partition, which is reserved for my
own personal files (not linux applications) will serve pretty much the
same purpose, so the three partitions I created will be all I need.

what you must understand is that all you need is a / (root) partition, and maybe a /boot.

Anyways, what happens if you only have a / ? your /home, /var, /usr and all the other will be under /, on the same partition.

However, this is not recommended on a server, since you don't want user files (/home) or logs (/var) to fill up your drive and prevent the OS from working, so if they are on a separate partition, they'll fill their partition, without affecting the others.