Shed Drawings

I have not surfed, but you can certainly find general sketches, photos etc., showing similar to what you are looking for in a few keywords to search the WWW.

It may be more difficult to find posters and methods, guiding you from beginning to end.

I assume you have access to existing shed? If so, two copies at least in part, the methods used for its construction.

You want to build is a concept very well, but you can find problems, such as codes that must be followed, thus, questions of utility, etc.