What you need to know:
What is a network, PAN, WAN, LAN.
Advantages and Disadvantages of a network
Wires and Wireless
Topology (bus and star)
Protocols (HTTP, SMTP, TCP/IP UDP, FTP, IMAP, POP, )
IP and MAC addresses.
What do you want to know? Is there anything you don't understand? Please feel free to post, I or other students can help. For now there are a lot of videos for you to watch.