Advice on reading/learning about Apache Modules


I can't seem to find a better-suited newsgroup for my question,
so I hope it is sufficiently on-topic here.

Having a hard time finding online references that are complete
in terms of learning more or less in detail this subject. I'm ok
with having to go buy a book.

I find several recommendations to "Writing Apache Modules with
Perl and C" by Stein/MacIchern --- it is said that the book is well-
written, etc. But the thing is, it's a 1999 book, which from what
I understand, covers Apache 1.3, and nothing about 2.x --- would
this make it entirely useless? Or is it pretty much irrelevant that
they cover 1.3 or 2.x?

I see a more recent book (IIRC a 2007 edition), Nick Kew's "The
Apache Modules Book" --- but I look at the Table of Contents,
and it does not seem too convincing (then again, I don't
necessarily have enough information to judge whether the
content is appropriate or whether the book seems good by
just looking at the TOC).

Any advice? Any pointers to online reading/tutorials that I may
have missed in my searches? (in the Apache web site itself, the
Developer zone, there seem to be articles on specific subjects,
but they strike me as having a target audience of people that
already know the basics about developing Apache modules and
cover specific techniques or tricky aspects --- am I off in here?)