I've never seen a good one. I've seen a lot of lousy ones.
The most detailed site for beginners -- imperfect but decent,
is actually Microsoft's -- but oddly enough it's the VBA
Programmer's Guide for *Office 97*:
http://www.microsoft.com/officedev/articles/Opg/toc/FULLTOC.htm
The concept are the same, as is probably 99% of the code.
Just be aware of the outdated nature ('97 isn't even supported
anymore) if you come across anything that doesn't make sense.
There's also a wealth of macros at the MVP site, but much of it
is aimed at specific problems and perhaps not 'elementary' in
the sense you intend. However, any beginner should read most
of the article on the 'Beginners's Tips' section of the site's
Macros/VBA tab. Notably most helpful for me, and still IMHO a
'must read,' is Bill Coan's 'Getting to Grips with VBA in 15
Minutes.'