I do most of my reading on my Cybook, and experimented for some time to find a font face and size, along with para indent and spacing that I was most comfortable with. I wanted it to look good (for me) primarily on the Cybook, with a PC screen as a secondary device.
I chose a couple of Roger Taylor's Hawklan Series books, since they are simply formatted with <p>text</p>, are nice and large, and I enjoy re-reading them. I found that on the whole I preferred the serif font family, with a font size of third or forth up from the smallest on the Cybook. I'm quite happy with the default 'Georgia' font, though I have tried others.
Having selected the font, I narrowed the spacing options down (using em's and %'s), then fine-tuned using px, to get to my current paragraph css settings, which are:
Code:
p { margin-top: 10px; text-indent: 25px; }
.p { margin-top: 10px; text-indent: 25px; }
The whole process took me about three weeks.
It would be good to be able to change these on the fly, as you can with justification (if it hasn't been forced), but I keep the source, so a minor edit at the top of the file along with a recompile is simple (and easily scriptable) should my reading preferences change.
The .p class, incidentally, is for "paragraphing" within blockquotes using <div class="p">, since the mobi reader always seems to terminate the blockquote at the first </p> that it finds rather than at the closing </blockquote>.
Snowman