Pages is a word processing and desktop publishing application. In our district AppleWorks has been replaced with Pages.
If Pages is not in your dock, you will find it in your applications folder, inside the iWork '08 folder. iWork '08 includes Pages, Keynote, and Numbers. If you plan on using these applications on a regular basis, you'll want to drag the icon of each application into your dock so they are handier to get to.
Do you use Keynote? If the answer to that is yes, then you're well on your way to understanding Pages. You'll see some of the very same features in both applications: the inspector, media browser, masking, shapes, tables, charts, and lots more. So learning one of these applications will automatically qualify you as an expert in the other application!
Check out the wiki on Pages which includes tutorials and ideas for using Pages. Use the table feature to create bingo cards and trading cards. Use the shapes to create Venn diagrams and for masking photos. The poster template is great for creating 8 x11 posters and 11x17 inch posters. Several ideas are listed for using posters in the classroom.