I am a junior developer working on my own in the programming aspect of projects.

I am given a png file with 5-6 of the pages designed, most times in specific detail. From this I'm asked to develop the back end system needed to maintain the website, usually a cataloging system with products, tags and categories and match the front end to the design.

I find myself in a pickle because when I make decisions based on assumptions about the flow of the website, due to a lack of outlining details, I get corrected and am required to rewrite the code to suit what was actually desired.

This process happens multiple times throughout a project, often times on the same detail, until it's finally finished, with broken windows all through it.

I understand that projects have scope creep, and can appreciate that I need to plan for this, but I feel that in this situation, I'm not receiving enough outlining details to effectively plan for the project, resulting in broken code and a stressed mind.

What should be the minimal design/scope documentation I receive before I begin development?