Look through a series of your photos, attempting to develop a common theme or idea for your collage. For instance, if you have a series of photos of one particular person, perhaps a child, you might select photos you can arrange in chronological order starting at the top of your vertical collage -- showing the child reaching various milestones as he gets older, with each photo below.
Place your selected photos on a desk or table. Also place a piece of 11-by-17-inch card stock on your work surface, oriented vertically.
Assemble and rearrange your photos on the paper, cutting them to fit as needed, with scissors or a precision knife. Use a ruler to measure them out evenly in a vertical stack, if desired. Or cut out important people, places and things from the images -- staggering their arrangement and overlapping them slightly. You can also create a color scheme with photos, even using pens or markers to embellish the paper in between the images.
Apply a light, even layer of glue to the back of each picture, and affix it to the paper. Continue gluing your photos until they're all in place. Allow the glue to dry for at least an hour.
Place the collage into a frame, if desired.