Canon has a "tech guide" for our beloved PowerShot S1iS, called the "PowerShot Technology Guide." You can download the 12-page, 2.2MB PDF file from Canon USA.
It's not so much a hardcore technical guide, as a low-level introduction to the technical features of the S1 and Pro 1. Plus, you have to wade through marketing-speak, like "Canon is uniquely positioned..." Still, it's free, and a worthwhile read to better understand some of the inner workings of your camera.
It's not so easy printing the tech guide, because Canon assumes you have a B-size (11"x17") printer. Notice the images at left: two pages per sheet.
Here are the settings I used in Acrobat to print on standard A-size (8.5"x11") paper:
Paper Scaling: Tile large images (fits each B-size page on two or more A-size sheets of paper)
Tile Scale: 85% (forces the tile to fit onto just two pages)