Better just to give written instructions?

Better to actually talk with them, whether in person or over the phone. Unless you know the specs you want (for example -- and this is only one component of a book design -- font, font size, leading -- for (1) body text, (2) various levels of headers, (3) footnotes, (4) references, (5) figure captions, (6) tables, (7) appendices, (8) etc.) and can delineate them very precisely in a written document that details literally everything, then a vocal conversation in real time, whether in person or over the phone or Skype or whatever, is the most efficient way to do this while minimizing confusion and frustration.

At least, that's what I would ask for if I were the designer. If someone could give me written instructions that detailed absolutely everything -- including margin/gutter/trim size; figure/table runaround; style for page numbers; style for headers/footers; content of headers/footers; style of the TOC; style of the index, etc. -- then that would give me a starting point, although I would probably still have a boatload of questions, because I never, EVER work under conditions in which the author wants me to "read [his] mind." That way lies fights, tears, recriminations, and the very strong possibility of a kill fee.

t edit At work, where we are all in the same room, the process of designing a new book from the ground up is difficult enough (granted, part of that is because half my co-workers just wave their hands vaguely and say things like "make it POP!"). And that's when they're articulating what they want, not expecting Chatty and I to read their minds based on a mock-up.

Mock-ups can help for basic elements; I'm not saying they're useless. If, for instance, you know you want every page to have a flush-left header with a rule under it that extends the width of the live area, a mock-up can show that very clearly. But an actual conversation is always going to be much better than a mock-up or incomplete instructions, or the hope of mind-reading.

NoiseD: In the abstract that makes a lot of sense. How does that translate to how I work with them? Before I start approaching professional I need to learn how to be client for this kind of work. Cause using any type of professional is a skill. If it were lawyers, my late father taught me about lawyer management. But I don't know anything about how to get the most out of working with graphic professionals.

Teppy: things like fonts and gutters are one of the areas where I would want to professional to make the decisions. I can give criteria like - no fonts or backgrounds that detract from readibability. Readibility is priority over artistry. But font is one of the decisions I want a professional to make.

Also - each 2 page layout will have three components - a graphic, a very short text, extended text. I want to reader to look at the graphic first, then the short text, then the extended text. A layout artist is the person figure out how to do that, not me.

How does that translate to how I work with them?

You need to have some sense of what you want. Not specs like font/leading, but what kind of design in terms of contemporary, traditional, minimalistic, etc. Look at books whose design you like -- though not necessarily want to copy -- and figure out what you want. Start with that.

On a project as big as a book I'd start by finding a number of designers that you think you might like. Then schedule a time to sit down with them an examples from their portfolio and talk in very broad terms about layout ideas that you like or dislike and look through their portfolio for layouts that strike you as heading towards the style that you like.

The next step from here is going to vary a depending upon the person you are working with. They may want some broad form mock-ups from you, they may want to mock up some example sections on their own and then run them by you for review and approval. Once you are headed in the right direction then you need to set up very clearly defined milestones and buy off points. This will help catch areas where your two design ideas may be diverging.

My experience working as a creative professional is that I can give my clients the most when we are regularly checking in with each other and there is an open line to push each other's aesthetic. My clients will almost always bring something to the party that I wouldn't have thought of, and I will almost always bring things to them that they hadn't considered.

But font is one of the decisions I want a professional to make.

Then you need to let them know that and delineate it in the contract. Because I have worked with clients who have said similar things and then shot down not one, not three, but four sets of specs I gave them, after they said the -- I don't mean to be snarky -- very disingenuous statement "oh, you decide that! You're the professional!"

Also - each 2 page layout will have three components - a graphic, a very short text, extended text. I want to reader to look at the graphic first, then the short text, then the extended text. A layout artist is the person figure out how to do that, not me.

Right, but you need to be able to tell them what you just said right there. So that paragraph -- that's a good start.

Wait. I obviously skimmed, but I just went back and read the pertinent posts -- Typo, what is your publisher creating out of your content? It sounds like not a book. Am I wrong? Are they not doing the layout and design of your content? And if not, how are they publishing it? IOW, what format? Are they making an actual physical book, or something else?

OK what my current publisher is creating is a book. A book that is all text except for 18 graphics out of 210 pages. (16 of the "graphics" are tables so not what I normally think of as graphics.)

I want to create a graphic supplement. 200 pages, but mostly graphics with less than 10,000 words of text (maybe a lot less). In the supplement I envision, each 2 facing pages that includes: 1) A large graphic 1/2 to 3/4 of the page (not including margins). A single sentence that combined with the graphic conveys the key information in those 2 facing pages. Extended text that explains in more detail, gives an informal citation if the point needs proof and tells where to go for more information (about 100 words on average perhaps less). The book my publisher will release in Novemember is very academic. This supplement is intended to be informal and (if it is OK to use the word on a horrifying subject) entertaining.

Instead of Entertaining, try Engaging.

Engaging is indeed the right word.

Are you planning to sell this supplement, TB?