I would like to find a definition of computing and a definition of
information technology.  I would like to know what, if anything,
diferentiates the two terms, which are often used interchangeably.  I
am particularly interested in knowing what would distinguish a
computing professional from an information technology professional. 
My sense is that this is an area where people would have many 'gut'
reaction type opinions based on their working experience.  I would
like to move past that level of understanding and I seek information
from authoritative sources.

Wow, I see what you mean. Wherever you look the two terms seem to be
used interchangeably.  Technically speaking however, they aren't quite
the same thing.

In short, Information Technology is a group-term that encompasses both
computing and telephony. That is, both the hard and soft components of
the computer itself, and the manipulation and movement of the data.

Computing refers to any aspect of using or developing programs for a
computer to create, store, and manipulate data.

"IT (information technology) is a term that encompasses all forms of
technology used to create, store, exchange, and use information in its
various forms (business data, voice conversations, still images,
motion pictures, multimedia presentations, and other forms, including
those not yet conceived). It's a convenient term for including both
telephony and computer technology in the same word"
http://search390.techtarget.com/sDefinition/0,,sid10_gci214023,00.html

"… Information Technology means the use of hardware, software,
services, and supporting infrastructure to manage and deliver
information using voice, data, and video."
http://www.state.nd.us/itd//planning/definition.html

"Information technologies (IT) means data processing and
telecommunications
hardware, software, services, supplies, facilities, maintenance, and
training which are used to support information processing and
telecommunications systems."
http://www.budget.state.ri.us/techinfo00.pdf

Just to refine the definition further, by telephony we mean:  "the
technology associated with the electronic transmission of voice, fax,
or other information between distant parties using systems
historically associated with the telephone, a handheld device
containing both a speaker or transmitter and a receiver. . .  
Internet telephony is the use of the Internet rather than the
traditional telephone company infrastructure and rate structure to
exchange spoken or other telephone information."
http://searchnetworking.techtarget.com/sDefinition/0,,sid7_gci213113,00.html

Some of the "core positions" involved in strictly defined "computer
professional" fields would be:

COMPUTER SCIENTISTS:   design computers & conduct research to improve
their design or use, and develop & adapt principles for applying
computers to new uses.

COMPUTER ENGINEERS work with the hardware & software aspects of
systems design & development.

SYSTEMS ANALYSTS...study business, scientific, or engineering data
processing problems & design new solutions using computers.

COMPUTER PROGRAMMERS write & maintain the detailed programs /software.
 http://www.cs.utk.edu/news/newsflash/Oct22flash.html

IT professionals focus on transmission of the data (that is, the
information on the computer) as well as the actual computer itself. 
These fields include such things as – data base management, LAN and
WAN professionals, Information/Data Modeling, information systems
management, and such.

However, you'll notice that whether we're talking about job
descriptions or course descriptions, these two areas seem to overlap
and merge. Very few companies or schools differentiate them.

http://gsb.luc.edu/progs/academics/infosystems.html
http://pgse.cis.drexel.edu/pgsit/About/courses.php
http://www.dnmyers.edu/courses/coursedescit.html

I would suggest that this is because the use (and development) of
computers is no longer a clear-cut separate entity from the
transmission of data between computers or to users.

This confusion and overlap between the two fields has been the source
of headaches for HR, job applicants, and potential students. Today
there are numerous companies, government agencies, and organizations
working hard to try to redefine job definitions to encompass the
changes.

http://www.perrymartel.com/articles%5Cospm.html
http://www.shrc.ca/news/2001/cata_conference.html

In summary, although we'd like to be able to identify standardized
clear limits on what a specific job title means in terms of training
and qualifications, there is no standard in place. At this point it's
anybody's game.

Hope this helped you out and that you've found the links useful. 

--K~

search terms used:
"Information technology" definitions
"Computer terms"
"standard job descriptions" Information technology

Thanks much!  I am definitely pleased with this answer.  I had already
put some time into the search, so I know it wasn't easy.  This
response definitely moves me ahead, and I particularly appreciate
including the search terms used.  That is a very nice touch.

Department of Labor (http://www.dol.gov) uses the Job Classification
from ONet Database (http://online.onetcenter.org/) to figure out 
the classification of jobs. You can see the exact definitions, job
duties carried out etc. in the Onet Web site.

-Raj