Creating, using, manipulating Pattern Swatches in Adobe Illustrator is a lot of fun, and very useful in many different web or print design situations. Especially for all kinds of background needs.
Creating a Pattern Swatch is most likely one of the easiest things to do in Adobe Illustrator. Select some objects, and then drag them into the Adobe Illustrator Swatch box. Once you have created the Swatch, then the real fun comes when you start manipulating how the patten swatches in Adobe Illustrator show up in you design.
Another interesting and useful things about pattern swatches in Adobe Illustrator is the ability to drag existing pattern swatches in Adobe Illustrator out of the swatch box, and them manipulate them changes sizes, colors, and other attributes of the swatch, then drag them back into the swatch box.
I´ve created a video on this process. You can see it at my sister site, sillybilly.com by clicking here.
I often refer students to this site, Digital Arts, presented in video format by Ben Steers.