Ahad-- Yeah, normal users can't use PM's on this forum. You only can if you are a paid supporter, I forget what they call that here, but thats what it basically is.

Now, as far asyour questions go...
1) Its normally better to have XP installed first, because then your Linux bootloader doesn't get overwritten by the Windows one. The bootloader Windows installs doesn't give an option to boot into Linux.
2) There are some good commercial partitioning programs available. I think Partition Magic is pretty good. The filesystem that XP uses by default is NTFS, and I am not sure how well it can be resized. If you could erase your XP installation, repartition the drive, and start over, I'd recommend that. I think some other distros have partitioning utilities that support NTFS resizing though, so you could just download the first ISO of Mandrake (I think it has such a utility), resize your partitions, save them, and then start the Gentoo install. The Gentoo installation handbook actually recommends a root (/) partition, a swap partition, and a /boot partition, so you may want to add another one besides what you are already planning.
3) As far as the Gentoo installation itself goes, I'd recommend a Stage3 if you are new to Linux. Others might say to just go for Stage1 though. Its really up to you. I would definitely print off the installation documentation/handbook though. Its available here. Its long, but Gentoo's installation is very different than most, there is no installer, and you control the installation directly from the command line. The installation handbook is excellent. I wouldn't have been able to get Gentoo working without it.

If you are really going to dive into Gentoo, you may want to look at their forums here in addition to LQ if you have problems.

If you have any more questions, let me know. Good luck.

Ah, thanks for clarifying alot of those points up.

Yeah, I'm going to do the full dive into linux and go with a stage1 install.
And yeah, I'm headed over to UTA to print off the handbook (gotta love free printing) because I'm going to need it.

The reason I asked for a repartitioning program was because I didn't want to reformat this drive - but I guess I have no choice, because I'm not willing to pay for Partition Magic when I can just as easily use fdisk after backing up important data.

Okay, well wow, that handbook really rocked I guess, cause here I am. I did a full stage1 install and dual-booted it with XP. I just rebooted to make sure GRUB worked right and I could pick between gentoo and xp.

So I guess all that's left is customizing my linux environment and getting some of the other stuff setup like Mozilla's browser & e-mail programs, etc.

It wasn't hard. Just long.

Blah, I knew it was too good to be true. There's some sort of root drive error on the gentoo boot.

Apparently my grub.conf file isn't configured correctly. The error message I get when I (attempt) to boot is something toward the effect of
"Append correct root=" which I don't understand.

My partition scheme:
hda1 - WinXP (40GB)
hda2 - Linux Boot (32MB)
hda3 - Linux Swap (1024MB)
hda4 - Gentoo Linux (60GB i think)

my grub.conf file:
default 0
timeout 30
splashimage=(hd0,0)/grub/splash.xpm.gz
title=Gentoo Linux 2.6.5-r1
root (hd0,3)
kernel /kernel-2.6.5-gentoo-r1 root=/dev/hda4 vga=792
title=Windows XP
rootnoverify (hd0,0)
chainloader +1

Am I mounting my root incorrectly?

EDIT: Moving this to it's own thread

I had some problems with my grub.conf similar to yours I think, soon after I installed...

I changed my root line to read root=(hd0,x) (so I added the equal sign)

I also changed kernel to kernel=

Give that a try...