I have been working (and still am) working with DITA-OT for PDF using the PDF2 plugin. For mastering (?) the plugin structure and capabilities I have based a lot on the fantastic book Dita for Print by Leigh Davis. Beside of other resources, this has been crucial.
I am beginning now with a journey around HTML and I wondered whether there is any HTML-biased book that might be my side companion book.
Thanks for the help,