Try and get some experience behind the Net+, get a packet sniffer like Etherpeek and just PLAY and learn new stuff.
See if you can also get the trial version of 2k3 server (you can use it for 180 days). Set up different services on it(mail,DNS,DHCP,http, etc), log onto them with another computer (and sniff it while logging in too!), and just keep playin with stuff to see what happens over the network, you'll learn a lot of important stuff.
Also check out little free apps like Superscan, which can scan lots of different stuff over the network. These will put a foundation behind a lot of the concepts and make you much more useful to an employer.