Linking the TI-83 can be done very easily and can provide a quick and massive oppurtunity for storage of programs, matrixes, and other files on the users PC. The link can also allow files (games) from the internet to be loaded onto the calc. Graph links are available in stores and over the Internet.
Next the user needs to download a link program from TI online. Since all of these programs are different, the best way to learn your system is to experiment with some files that don't matter if they get lost. Learn like I did - download and play!