Nothing beats real world experience. You can read all you want about the OSI model, Netware, and Token Ring, but it won't help you out when you need to reconfigure a simple VLAN or plan out changing your routing protocol from RIP to OSPF. Seriously consider the dual 2500 router setup if you have the cash (about $1000 last time I looked). Trying to learn networking without hands-on experience is like trying to cook Beef Wellington after reading the back of a hot-dog package.
-Jason