I'm interested in a part-time career in computer data recovery.  Are
there any recognised courses/career paths/books to becoming a computer
data recovery technician?  I've read on a forum that no such training
exists and it's very much "teach yourself".  (I've found courses on
"computer forensics" but that appears to be more about criminal
investigation than data recovery per se.)

No business can afford to lose valuable data.
Basically you need to be studying (or had studied) an enginering in
software or systems.  With your major studies you could course/career
to become a computer data recovery technician.

I suggest you to check out the next links:

http://www.digitalrecovery.com.br/english/training.htm

http://www.vogon-international.us/literature-vision-9-9.htm

http://www.cbltech.com/jobs.html

http://www.computer.org


Also maybe you should consider to request a trainee course/job in a
prestigious company dedicated and speciallized in the field.

http://www.dataleach.com/index.htm


Besides, just for the record, Computer Forensics is about of data
corruption and retrieval (most of rebuild all the sensitive
information when is lost phisically and/or electronically from all the
media) and you want to re-construct the causes or the origin of the
lost.


I really suggest you (encourage) to get speciallized (or thinking) in
that field.  There are so many necesities in data recovering and
retrieval for companies.
(http://anaheimca.citiesunlimited.com/datarecoveryservice.html)  Also
its a very well paid career.  Im myself a Systems Engineer but im
specializing in IT security.

I hope it helps.

Phossil