When you're done putting together all the pieces yours should look like this. This particular bridge was able to hold the maximum 30 pounds.
The objective of this project was to build a bridge using nothing but school glue and toothpicks. Our teacher have us credit for just simply building a bridge but gave us extra points for every pound it held with the maximum being 30 pounds.
First thing you would have to do is figure out which bridge design you want to go with for the main part. I decided to go with the Warren (with verticals) design but you should choose one that would be easiest for you or the one you think would hold up the best. I used this paper as reference of the different types of bridges I could build. The one I chose to build is in the third row third column.