Pages

First of all, you need at least two (but more is better) complete editions with all the pages.

The best is to get the pages in a format that you can open for editing and review in full comfort, e.g. InDesign or Quark. This means you need the same or a newer version of that software.

To have the original files is especially important in the phase of preparing a prototype.

If such formats are not available, then the pages in the PDF format can be sufficient.

Images

If you can get the original files, then ask for the high-res images. If those are not available, then you will need to extract the images from the PDF files. You will need images to measure shapes when creating sample object libraries.

Texts

If you can get the original page files, then - at worse - you will copy text via clipboard from the original pages. For some page formats might exist automatic import procedures. If you get only PDFs, then you will need to extract the text from the PDF files which is often cumbersome, i.e. you loose the line endings (all text is one paragraph), or paragraph endings (every line of text is an independent paragraph).

Have in mind that you will need to adjust the GN4 schema to handle all the article elements that product contains. In some situations you may however use the standard schema: if the product handles the byline as a separate element, you can still propose to handle it as a part of the body text.

Keep your eye on the blocks and blockheads.

Fonts

You need a full set of fonts, used on the pages. You will need to fonts when you start to build formats for the prototype.

Workflow description

You need to get a clear idea which kind of content you will receive to be made up automatically, which kind of categorization (if any) you can expect, and which kind of completeness (content with ready-to-use headlines, or without them).