Fold several sheets of the 8 1/2-by-11 cardstock in half crosswise. Fold as many sheets as you need for the pages of your pop-up book. Stack the cardstock together, lining up the folded edge.
Draw a line 1/4 inch from the folded edge of the top piece of cardstock. Make sure the pages are all even and then staple along this line to make a book.
Cut a 2-by-8 1/2 inch strip out of the regular paper. Fold this paper in half lengthwise and glue along the spine of the pop up book to hide the staples. Let the glue dry completely.
Fold the top page of the pop-up book back and use your finger to make a crease. Repeat for each page of the book.
Fold a piece of 8-by-9 3/4 inch cardstock in half crosswise and use the ruler to draw two straight lines about 1 inch apart on the fold. Make sure the lines are the same length.
Cut along the lines. Open the paper and push the tab toward the inside. This tab is what makes your picture pop up when you open the book. You can make more than one tab on each page for multiple pictures.
Open the first page of the stapled book. Glue the 8-by-9 3/4 inch paper onto the book, lining up the folds. Be careful not to glue the tab down.
Glue a picture onto the tab and write your text. The picture should be positioned to lie flat when the book is closed. Once the glue dries, fold the page back and forth a few times to make sure the picture and tab move freely.
Continue adding pages to your pop-up book until it is complete.