This brief section was added so that you may better understand network technology and therefore be able to use the network more efficiently. Reading this section is not necessary to get your data connection working, but it could help in identifying and correcting problems.
The network is made up of several layers that make that sharing, communicating, possible. The lowest layer is the physical, the actual wires, chips, light or electricity that the data travels on. In your installation you will put a card in to your computer and connect a special wire from that card to the port on the wall. Each bit of information you request from the network will bounce down that wire and into your computer. The next level is the the software drivers: these are special program that talk to your new network card and make the information received from the network avalible to the rest of your computer. The last layer is the network application: these are the program you, the user, runs to interact with the network, these are the email programs, and the WWW browsers, here you're telling the network what to do.
A network's only purpose is to share data between computers, and this is done by sending what is called a packet. A packet is analogous to a letter sent in the mail: on the outside it has the addresses of the sender and the receiver, and on the inside it has the information you are communicating. A packet has the unique address of your computer, the unique address of your recipient and in the middle contains the data you're sending. A computer can have several kinds of addresses: the network card has uses a hardware address to communicate with other physical hardware devices, the drivers use a numeric IP address to communicate with other computers drivers, and the applications use words for an address.
This information should be a sufficient background of the basic ideas of a network to help you out with further steps.