If you are intending to use Linux for a home or hobby purpose, rather than for a business or profession, then what's the urgency? Just boot back into Windows for a while, then return to Linux when you feel ready; there's no need to give up.
I have a HomePNA setup working with Linux. If you are unsuccessful in getting it to work with Mandrake 9.0, I highly recommend that you start with Redhat 7.3 like I did. If you read the
www.homepna.org site, the Linksys drivers were intended to work with the Redhat 7.x series. Once you get some confidence and knowledge working with Redhat 7.3 then you can experiment with newer distros.
If you have the hard drive space, why not keep two Linux partitions? Install Redhat 7.3 on one, so you can have a reliable distro as a starting point, and install Mandrake 9.x (or Slackware or whatever) on the other.
I first started using Linux (Redhat 7.3) in December 2002, so I consider myself a newb. However, I carefully prepared beforehand by reading lots of Linux materials (like the Rute textbook at
http://freshmeat.net/projects/rute/) and by lurking linuxquestions.org, justlinux.com and tinyminds.org. I got HomePNA 2.0 to install right away on my initial Redhat 7.3 setup, following the instructions on
www.homepna.org.
The big challenge for me was figuring out NAT masquerading through iptables. That took me weeks of intermittent hacking, reading HOW-TOs and lurking forums. While I was trying to figure that one out, I simply booted my Linux gateway/router back into Windows 98 and used Internet Connection Sharing when I actually needed to use the computer, and back into RedHat 7.3 when I wanted to work on iptables.
Now my gateway/router is working (still on Redhat 7.3), and I haven't booted it into Windows for two months. There's still lots to learn though: ssh, samba, apache, openH323...
Just keeping working on the problem; that's why they call it "hacking". Please post back with your progress.