Canon EOS Rebel XTi Instruction Manual page 127

Printing Images
The camera can be connected directly to a PictBridge
printer or to a CP Direct or Bubble Jet printer and print
images.
You can select a number of pictures and print them all in
one batch (DPOF).
(p.144)
About DPOF
DPOF (Digital Print Order Format) is a standard for recording
printing instructions (image selections, number of copies, etc.)
in the CF card. In this way, you can print multiple pictures in
one batch or give the printing order to a photofinisher.
Canonts PictBridge Web Site
The Web site below gives more information on using your
Canon camera with various printers, such as which paper
types to use.
http://canon.com/pictbridge/