gjh42:
The tutorial starts off at a more complex level than the fundamental, talking about /images/dvd/. Upload your thumbnail image as the base image name, like product001.jpg, in /images/ (the default location). Then FTP your medium and large versions of the image to /images/medium/ and /images/large/, naming them exactly like product001_MED.jpg and product001_LRG.jpg.
FTP additional image thumbnails named like product001_side.jpg or product001_blue.jpg to /images/, and large versions named like product001_side_LRG.jpg or product001_blue_LRG.jpg to /images/medium/ and /images/large/.
Be sure to name the base images such that you will never have one image's name starting with another image's full name.
You have hit the nail on the head "The tutorial starts off at a more complex level than the fundamental" - with all due respect this is the case with many of the FAQ's / Tutorials and is not specific to this site but to others also where the writers have trouble getting down to the basic level / standard of the inquirer - kinds like the nutty professor who teaches his class and they walk out shaking their head saying what was he talking about.
This often happens when people are being too brief in their responses or do not consider that the inquirer does not have the fundamental basics required to understand a "complex" explanation.
The tutorial in question is apparently an excellent explanation of how to have multiple images and how to name them but for dummies like me it doesn't answer the very basic level question of "How do I insert multiple images (different images) of a product on a product page" (from different angles, a this is the dimensions image, a montage of the product style etc etc).
I have read that tutorial many many times and it does not answer the question albeit it most likely answers "part" of the question in explicit detail so no offence to the contributor.
The "follow the bouncing ball" tutorials that start at the "turn the computer on" level tend to satisfy most inquiries first time (advanced level people can skip the "I know that stuff already" parts, the parts that when missing confuse the daylights out of the rest of us.)
See the comment above this one - maybe I am not the only dummie in here :D
p.s. another prime example of responses that address a level above the actual inquiry - it was an inquiry by me about page breaks - you GJH42 responded suggesting what AFO said was a good way to go - your response had "explanation" that I could understand - AFO's comment was another question, not an answer and meant nothing to me because I didn't know what "document - general" meant (it could have been a variety of apples for all I knew) however your response actually explained what document-general is, at least to a level that now gives me something to explore.
Again, no offence to you AFO, indeed many thanks for offering a response - I just hope you guys and others who may read this can see why we dummies ask the questions we do, even after spending hours reading tutorials and searching this forum before making a post :D
cheers,
Mike
