Personally I have found google to be the best resource for learning about Linux. Generally my learning has revolved around resolving issues, rather than trying to learn (I learn best by doing rather than reading...)

In my travels i have found that Linux (in relation to TKL anyway) info falls into 3 catagories; generic Linux info (that applies generally to all/most distros inc TKL); generic Debian/Ubuntu info (which mostly applies to TKL) and specific Ubuntu info (which applies directly to Ubuntu and derivatives inc TKL). The tricky bit can sometimes be working out which is which and for me that has just taken time. For example Apache2 info; most general info falls into the first catagory but when it comes to config, while the theory remains the same, specific files etc are in different places and called different things (so falls into the 2nd cat).

The Ubuntu Server guide is quite an invaluable piece of documentation. 

If you want to learn more about Linux I suggest that you ditch Webmin and start using the command line. It's a bit of a learning curve but if you are doing it for your own interest then it's a good way to go IMO.

Anyway... As for you current plan to install your printer, my suggestion is that you first find out what drivers you'll need (sounds like you've done that bit). Now see if they are available already from the Ubuntu repos (internet repositories of installable files aka packages). You can do that with the 'apt-cache search' command (after updating your local package database by running 'apt-get update'). The other (and easier IMO) way is to use the web to search for the package, namely packages.ubuntu.com. If you scroll down you can do a keyword search of packages. Defaults are fine to start with except you'll want to change the distro to 'Lucid' (TKL v11.x is based on Ubuntu 10.04 aka Lucid). If nothing shows up, click the radio button to search 'Descriptions'. Once you have the package name you want (assuming that it's there) then you can install it with 'apt-get install <packagename>' (if you haven't recently updated your local package DB then run 'apt-get update' first).

If it isn't in the repo then you'll need to download and install manually. The .deb would be preferable (the .rpm is for Red Hat based systems so generally no good to us with TKL and the tar.gz/.tgz is a generic Linux archive (ie like a zip file) which will probably work but will be more involved). So once you have downloaded the .deb install it with 'dpkg -i <packagename>.deb'. Sometimes that will fail because of missing dependancies (ie packages that are required by what you are trying to install) but it should list what it missing in the error message so just try installing them with 'apt-get install <packagename>' and try installing again with dpkg.

Any other questions don't be scared to ask, although if they aren't related to network printing probably best to start a new thread.

Sounds good and good luck with it! :)

I suspect you are right and it is a permission issue and/or Samba config issue.

TBH I've never actually done it so from here on in it's blind leading the blind...

What I'd be inclined to do it make the permissions as promiscuous as possible (I'd use Webmin if you're not already) and see if you can get it working. Then try and screw down permissions until it doesn't work. Sorry that's probably not very useful, but it's all I got...