Foundations of Networking

This is a course ware available in the following site.
you may go through the first chapter of this book to learn about the history of networking and basic concepts of networking

http://www.netguru.net/book_ntc.shtml

The slides to support the learning of above concepts can be downloaded from
http://users.ictp.it/~radionet/1997_workshop/networking/notes/sld010.htm

You can also view the following videos from the folowing sites.
Data Communications & Networking

Course contains: Types of Networks (Point-to-point Connections, Circuit-switched Networks, Message-switched Networks, Packet-switched Networks). Types of Equipment (End Systems, Intermediate Systems). Types of Packet-Switched Networks (Wide Area Networks (WANs), Internet Service Providers (ISPs), Local Area Networks (LANs)). Types of Communication (Client to Server, Broadcast, Unicast and Multicast, Simplex, Duplex and Half-Duplex Information Flow). Open System Interconnection. Protocol Layers. Communications Between Layers.

http://cpe.njit.edu/dlvideos/CIS/CIS652/

Data Communications and Networking;
Data Transmission; Transmission Media; Signal Encoding Techniques; Digital Communications Techniques; Data Link Control Protocols; High-Speed LANs(3 parts); Wireless LANs; Cellular Wireless Networks; Internet Protocol; Internet Protocol Version 6(IPv6); Routing in Switched Networks; Transport Protocols; Network Security; Network Management (SNMP); Hypertext Transfer Protocol(HTTP); an overview of ATM networks
http://www.cs.wustl.edu/~jain/cse473-05/index.html