Ok here's a good one to help out a newbie.
I recomended to my grad school to go to open source software which they did, but they put me in charge. So keep in mind with any answer that I am a newbie and not very good with networking.

I need to be able to authenticate 20 linux boxes running mandrake 10.0 against an SMB server which holds a list of about 400 student and faculty profiles. Part of this is so that people at the school can acess their share spaces but also because it will be (hopefully) easier than loggin over 400 users on each box. Any help will be greatly appriciated.
Also, does anyone know an easy way to enable networked duplex printing?

Well, you being the grad student with a Bright Idea, you have been
granted the supreme opportunity to Learn Something. 8)

The scope of the project seems more than sufficient for using
a LDAP server for containing the user account database, unless
the SMB server you mention is supposed to be the authoritative
source of all identification and authentication information.

More information about the SMB server is in order, as well as an
indication of the linux boxes being intended for use by one person
at a time or many?

The linux boxes may participate in a Windows Domain or a Windows
Workgroup, and one could even serve as a Domain Controller.

Linux Journal had a very excellent series of articles about
a LDAP implementation - it starts here.
Part II and Part III

Aw, and here I thought I was learning too much already. Sarcasm aside, thanks for the information so far. It does interest me independant of whether or not I can use it.

I'm reading through LDAP articles, but the boxes are supposed to take their authentication from the SMB (samba right?) for all identification and authentication. Any student or professor is supposed to be able to log onto any of the linux machines. Also, please let me know what additional information is needed on the SMB.
Thanks for your help so far.

There are two alternatives for your overall system design, as I see it.

One is to have the SMB server be the holder of the authentication and identification
database ("user DB" will be the shorthand I'll use for this). Typically, in Windows fashion,
this is the Domain Controller.

However, whether or not the SMB server is itself Windows-based, it may be a Great Pain
to have to maintain the user DB on the SMB server.

That's where the LDAP server enteres the picture. The LDAP server would be consulted
by all the systems on all matters "user DB". And now you can adjust and maintain the
user DB in the way you think best for the kind of maintenance job you have at hand.

Otherwise, you may be forever making both user account and Samba account changes
here there and everywhere...