On the site of the Irkutsk's linux group there are two files
http://Lug.irk.ru/files/tenalg.tgz and
http://Lug.irk.ru/files/max.tgz. The first one contains the
introduction to itensor (in pdf and tex formats). The document
is in russian so far, sorry. The difference with the known
manual by Pavelle & Wester is that I put the material in the
systematic way, skip the non-working functions and add the
description of some new ones (which are in max.tgz).
The demo extracted from introduction is in max.tgz.
I'm enjoyed very much presenting two exercises from the book by
T.Frankel "Geometry in Physics" which were solved with maxima.
You can find them in ten_alg.demo in max.tgz. They are about the
conservation laws in ideal MHD.
The introduction was written with great help of emaxima, thanks
to Jay for the fixed bugs. Some of the proposed functions is
essentially relies to new nset package, many thanks to Barton &
Stavros.
rgds,
V