There is a ton of knowledge that CAN be learned. But the basics are the hands on to connecting machines.
http://pcworld.about.com/magazine/1812p268id32216.htm
http://articles.techrepublic.com.com/5100-1035-6089187.html
Cisco Alternative
http://www.vyatta.com/products/training/index.php
Also, asking specific questions is a good idea.
For example, in an office with eight computers, each of those computers will be connected back to a Hub or better yet, a switch. (The difference between these two is important wikkipedia is great for this). The switch then connects to either a firewall, or a router with some firewall ability. This router uses a process called Network Address Translation (NAT) to allow a private IP address onto the internet. There are many inexpensive diagram programs, but I have always used MS Visio. Even an old copy will do the trick nicely.
Barts suggestion of the Networking for dummies book was excellent. It will give you the basics in an easy to use manner. The cisco ccna book/s will then give you a mix of general network theory and design and specific cisco networking.
Some basics to learn right off:
What is a router
What is a hub
What is a switch
What is an ip address
what is a mac address
what is dhcp
what is dns
what is binary notation
what is hexadecimal notation
what is the OSI model
what is rfc 1918
Knowing what these terms are is a first step. After that, you can begin learning about each part and fitting them together like a puzzle.
I am sure others would add to this...
All of this is available on-line, with no need to purchase a text, but a text is easier to read, and will most likely go into greater detail.