I send this off to support@coolreaders.com (and completely forgot that the name of the device is "Cool-ER," not "coolreader." Oh well.)

I'll let you know what answers I get. In the meantime, if anyone else has answers, I'm happy to collect those as well. FWIW, I'm not looking at buying a Cool-ER; I believe I could get another PRS-505 for about the same amount. But not everyone has that option, or wants it. And I'd like to know Cool-ER's official answers to these, as well as the info that "we all know" because we know what company makes the basic hardware they're selling.

* Is there a user manual for the Coolreader, and would you consider making it publicly available so that people can understand the features before they buy?

* Does the Coolreader support folders? (If I create folders in the Coolreader, will the interface let me click through those to find the books I want, or does it just sort them all by title/author, and I'd have to remember what category they are?)

* Does it need or want software--is there an interface, perhaps some kind of library program that allows editing of metadata or sorting of categories, to manage books and move them from the computer to the Coolreader?

* How many shades of grayscale does it support?

* What DRM'd formats does the Coolreader support?

* Do any of the books sold at Coolerbooks.com require DRM software, or are the books sold there without DRM?

* The books listed as "Digital Editions"--are they ePubs, or PDFs? While both read about equally well on a computer, they aren't the same when transferred to portable readers; I'm much more interested in ePub books than PDFs.

* Is there a way to filter searches at Coolerbooks by filetype, to say "only show me books by [AUTHOR] in filetypes I can use?"
Got a reply back this morning; his comments in bold.

> See ansawers [sic] below

About the manual:
> See Quick Start Guide on this page:
> http://www.coolreaders.com/specifications.asp

Quick Start Guide is at http://www.coolreaders.com/pdf/quick-start-guide.pdf; it's basically a guide to the buttons in the device. At page 3, it says:I wrote back to ask where that was.

>> * Does the Coolreader support folders?
>Yes

Simple enough.

>> * Do any of the books sold at Coolerbooks.com require DRM software, or
>> are the books sold there without DRM?
> Most are DRM..check it out

I wrote back to ask how to tell which ones are DRM'd.

>> * How many shades of grayscale does it support?
>eight

>> * What DRM'd formats does the Coolreader support?
>See tghe specs page above

Spec page says ADE: ePub and PDF only. So the info given to Sassinek in this other thread ("So, yes, you can use DRM .PRC files") is almost certainly wrong.

>> * The books listed as "Digital Editions"--are they ePubs, or PDFs?
>can be both... this is an originator decision

Wrote back to ask if they'd answer which one is which for specific ebooks.

>> * Is there a way to filter searches at Coolerbooks by filetype, to say
>> "only show me books by [AUTHOR] in filetypes I can use?"
yes this is done by device on the home page..check it out

Wrote back to say I couldn't figure out how to do this. The search engine only seems to cover author & title, and it turns up results including all types of books, regardless of what reader you have selected. Once you click on the book itself, it may tell you "Not available for your selected reader(s)," but the site doesn't seem to have a way to not include those in the search results.
Wow! You got an answer back in less than 24 hours ... on a Saturday! Either they aren't very busy yet, or they have great customer service.
Next set of answers.

User Guide:
DRM:
Search for books by filetype:

We already know that Mobipocket has to be the exclusive DRM. So since they have Adobe's DRM, they cannot have Mobipocket's DRM as well.