I was just like you 8 month ago, when I was looking at my first linux dvd (mandriva 200, wondering what the hell is this all about!!? But after following the LPI series 1 &2, and ohter certifications study guides like Suns Certified Systems Engineer, I'm now comfortable working with my best Linux OS, openSUSE11.2!!! If you wanna advance in linux, pick up any linux based certification guides out there, Linux+, LPI 1,2 &3 (Linux Professional Institute Certification), Suns etc, and you're good to go!
One more important thing, and the main reason why i ventured into Linux is that, if you're thining about ethical hacking, and all you have is windows!!!? You're lost 4Life!