I've heard from all of you, now! Thanks to all.
Content can be pretty much anything, although leaning toward photos makes sense. Higher resolution pictures are probably better, but we can work with anything, really. Captions and accompanying text, as you like (or don't like). If you gave in mind specfic pairings or groupings, pass them along. Essentially, if you have ideas of any sort, communicate them. If I disgree, we'll have a conversation and try to come to some mutually pleasing arrangement.
I aim to be experimental! One photo centered on each page, for page after page, ain't quite what I had in mind, although I'm not opposed to some of that, so if you have some whacky idea, by all means. We like whacky ideas.
This is intended to be collaborative, to whatever degree you like. You may send me pictures and then lapse into silence, or you can send me a dense file of ideas and we'll collaborate. The only restrictions are, really: I do not have infinite time, and I get the final say. And that's just to keep it from getting out of hand.
Also, contact information. I'll devote some space to credits, associating content with the artists. You can be "anonymous" if you like, you can give an email address and first name, or your full name and home address. You can give a web site. A handful of words for a bio? However you would like to be known (but please keep it pretty short!), share that with me as well.