Can Redhat Desktop be installed as a server (with the help of Samba)?

What kind of server?  I don't see why not.  There aren't, to the best of my knowledge, any limitations to it.

RedHat Desktop Linux is shipped with different packages bundle than Enterprise Linux.
The kernel and the system libraries (glibc) are all the same.

However, you need to download the source code to compile them into binary yourself
the binary rpm doesn't come with RedHat Desktop.
Also, you won't get support for the installation and bug fixing for those softwares.

Other than those, there is no different between RedHat Desktop and Enterprise Linux.
(Well, RedHat Desktop only support single CPU.)

Samba comes with RedHat Desktop. So you can setup samba server and share out the folder
to Windows PCs.
The latest version of Samba has better support for integrating with Active Directory, so you
might want to download and recompile the SAMBA by your own.
http://www.samba.org/

So, out of the box, Redhat Desktop can not act as a server for a windows workgroup?? I'd have to compile different packages into binary for it to have this capability? Then implement Samba?
When the XP machines of this workgroup are configured to log into the domain that is created, will they use a different profile (user environment)?

I'm sorry that I sound like so much of a wuss...it's just I've never installed, configured, even used Redhat (or Linux) at all. I just want to make sure I know what I'm getting into.
Thanks.

"Out of the box" as in clicking on a pretty GUI icon to make the box a PDC, no.
"Out of the box" as in the default configuration being capable of becoming a PDC, basically yes once Samba is installed.

Samba can be a bizzatch to set up it's more advanced features, though (kinda like Sendmail...entire books have been written on it's configuration)...and if you're brand new to linux, you'll be in for a conusing ride.

I'm not familiar w/ redhat desktop in particular...my impression is that it is just another linux distro but one that you pay for and get (some) support with.  I guess it may have cushy lil centralized management utils tho, which would warrant the price in some situations.  I seriously doubt their support would include helping you set up samba as an active directory domain controller tho, so you'll be having at it solo.  Therefore, a better choice may be to use a different, free and unsuported distro just for the samba server (if a supported commercial linux server solution that can act as a PDC is too pricey for ya).  You can still stick w/ redhat, just use their Fedora Core 3 version (free).  I'm a debian junkie myself, but linux is linux...just the default package management methods, default packages and libraries included, and locations of certain system and log files differ from distro to distro for the most part.  You can install pretty much anything on any distro...even as far as using RPM utilities on Debian, apt-get utils on Redhat, etc.  

See https://www.experts-exchange.com/questions/21393254/MAJOR-PROBLEMS-Samba-Fedora-Core-3-as-PDC-Windows-XP-Pro.html for some info on using Samba as a PDC on FC3.

My gut feeling is you're biting off more than you can chew...but at the same time you'll learn boatloads of fantastic info on linux in general if you decide to jump in and get your hands dirty, weather you wind up being successful at setting it up the way you want or not.  If this "has to be done by Friday" to keep your job, I'd suggest getting your resume together and start lining up interviews, but if you have time and can accept having to do a lot of reading and troubleshooting, joining samba user email support lists, etc and can wait for replies (i.e. you don't need to be able to pick up the phone and get an immediate answer) then by all means have at it and gain the knowledge :).

I focused on AD since you said "When the XP machines of this workgroup are configured to log into the domain that is created", but if you're just needing simple file sharing as a workgroup and not an Active Directory Domain, then the Samba configuration would be simpler.  It really depends on what kind of access controls you're going to need.  If you just need a LAN-public, generic, "everyone can read/write in this folder" kind of samba server, that can all be point-n-clicked to set up via webmin if you install that and samba.  You can get some more user and file/directory control as well through webmin's samba module, but you can't take it to the level of being a PDC in an AD environment that way.

If a doze workgroup environment fits your needs, you may be fine (tho I'd still do it on a freebie nix distro instead of redhat desktop for the samba server).

> doubt their support would include helping you set up samba as an active directory domain controller
Don't need to doubt, it is not supported.
RedHat Desktop Linux support is for RedHat OS installation and patches update. Nothing else.
Similar to Windows, which support for OS installation and OS bug fixing, M$ doesn't support the IIS or
any third party server softwares setup on Windows OS.
That's the system administrator's or your own job.

Check the RedHat manuals, which give you more details how to setup SAMBA or other server software.
Specially,
Red Hat Enterprise Linux Introduction to System Administration:
http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/admin-guide/

Red Hat Enterprise Linux System Administration Guide:
http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/sysadmin-guide/

Red Hat Desktop Deployment Guide:
http://www.redhat.com/docs/manuals/enterprise/RHEL-4-Manual/desktop-guide/

I don't necessarily want to integrate this computer/server into the Active Directory. I just want to create users on the Linux box, create shared folders, share the  folders out, and be able to have the Linux box (redhat) govern who can access what folders (based on it's own security scheme).
Is this possible? If so, is it something a Redhat nivice can accomplish? Is there a better Linux distro to use for this?
Thanks