1) Of course, networking skills often are useful in a systems/network administration environment. That being said getting a RHCE without knowing linux is A) going to be extremely difficult and B) Worthless. If you're looking for a certification to 'learn' about linux a better choice would be Linux+ or LPIC1. They cover more basic issues you're going to face often. RHCE covers a lot of very RH specific items which won't apply to a lot of linux and unix you're going to use in the field (I've been responsible for servers running Debian, Redhat, SuSE, Slackware, Devil, CentOS, Ubuntu, FreeBSD, NetBSD, OpenBSD, BSDi, Irix, SunOS, Solaris, SCO, and Windows NT3.51-Server2k8.) Diversify your skill set is good advice if you're planning on a career in systems administration you're going to need to know ~many~ operating systems in all likelihood.
2) Use it. Blow your windows off your computer, install a non extremely user friendly Linux variant (try Arch, Gentoo, Slackware (*ducks*- Don't get me wrong, slack is not hard, but it doesn't cuttle you like say ubuntu or mint), etc.) setup the services you might see in the field and use them locally, fix the problems you encounter. Setup web, mail, ftp, web apps, ldap, sql, integrate your apps, etc. Once you get all the bugs worked out move onto a new distribution until you feel pretty comfortable on any distribution. It takes time. You've got to actively use the system or you'll never really know it well enough to admin it.
Last edited by rweaver; 02-24-2010 at 03:03 PM.