Good morning Rock57,
Thanks for your question and welcome to the community.
You'd be extremely hard-pressed to find a materials list for any size shed due to too many various factors like, type of lumber, type of windows....just for starters.
If you have a schematic or even a picture of the gable shed you'd like to build, your best bet is to come into your local Home Depot store and speak to a Pro Desk associate who can assist you with the materials and put it all on one quote.
A quote doesn't mean you need to buy anything; but it does organize everything onto one order sheet, so you can get not just specific materials, but also specific pricing. I really can't stress this enough; since having someone in person can mean the difference between a thousand (or more) dollars and more materials.
Let us know if you need anything else.
Joseph