Your telepathic! - i was just about to write a similar post.
To respond first
> a) The Official Ubuntu Book (1st edition, 1st printing, Aug. 2006)
I looked at that book and reckoned it was a complete waste of time
other than the recipe for a ubuntu loaf.
> chmod 777 (x.x) would give me all permissions. Wrong.
> chmod a=rw (x.x) did. Why didn't the 777 work when a=rw did? Is it
> something to do with Ubuntu?
> There are many places on the net that talk about doing it but showing
> me how to do it they fell short.
My sentiments exactly. I've just been trying to learn about
permissions and not finding it easy. Still unsure the 777 worked but
i'm not sure why.

> What books do you consider to be the most authoritative books on
> Ubuntu/Linux?
Difficult to answer as with Linux development is fast so by the time a
book is written it is almost out of date. I bought Ubuntu Linux by
William Von Hagen [better than many but a little brief on technical
things like permissions], and Ubuntu Hacks by Jonathan Oxer [better on
technical things]. I'd say i had my money's worth. Used Beginning
Ubuntu Linux from Novice to Professional by Keir Thomas from the
Library [heavy on apps and covered some reasonably technical stuff].

Books like Linux in a Nutshell - no particular distro tends to be full
of technical stuff which is more what i'm after i think is the route
to go down. I'm just looking at some books this w/e and i'll post what
i've chosen. Ideally one needs a local library that has a good stock
of linux books - often there are a few chapters in each book which one
finds particularly helpful and the rest!