The bag pattern I started with was from a totally wonderful and well illustrated free Messenger Bag pattern from Larissa at mmmcrafts.
The bag wasn’t perfectly suited for a school bag however, so I made a few minor modifications. Larissa’s finished bag is 12″ x 12″, not quite wide enough to hold school books. So, I added an extra 2 inches to the width, and an additional 2″ width to the inside and outside pockets. I added two pencil holders to the inside pocket, and because the girls will be toting around books in their bags a Pellon Fusible Fleece to give the bag more weight and stability. Some other minor changes was to add a small loop near the side handle because my girls love to hang key chains or small toys from their bag. I also made the strap two colored, but that is because I was a little short on fabric. I only had around 3 inches left of the long 45″ strips and I did not want narrow straps! So I used the lining fabric on the reverse, and I love how it looks.
Here are the dimensions of the pieces for the bags I made:
strap, cut 2- 3″ x 45″ (For Lily and Emma I had to cut the strap down a lot… You customize the length when the bag is nearly done.)
body and lining, cut 1 each- 16″ x 25″
Pellon fusible fleece, cut 1 – 16″ x 25″
flap and flap lining, cut 1 each- 14″ x 13.5″ (I used a cereal bowl to round my corners, Larissa recommends a 6.5″ circle. I placed my fabrics right sides together, traced the rounded edge of the bowl and cut out the rounded corner of both the flap and the lining at the same time.)
outside pocket, cut 2 – 11″ x 7.5″ (again I cut one from the body fabric and one from the lining fabric)
inside pocket, cut 2 – 11″ x 5.5″ (ditto)
key chain loop, cut 1 – 1.5″ x 3″ (press in half, wrong sides together, then press a hem on both sides evenly. Stitch close the the edge)

I posted lots of photos and step-by-step instructions here as well: http://makeitdo.wordpress.com/2009/0...g-school-bags/

Enjoy,

Calli
Make it Do http://makeitdo.wordpress.com