Don't consider this an official statement, but I have found that learning shortcuts works best without any assistance. I learned InDesign shortcuts by slowly expanding my knowledge as I learned new tools.
These covers can help, but I think that they habituate you to look down at the keyboard, which somewhat defeats the purpose of keyboard shortcuts.
Also, I imagine InDesign can't be the only program you are using, the keys might get old after a while. A free option is to use an image of a keyboard that has all of the tools. This is one I found with a quick google search: http://www.indesign.com.mk/index.php/blog/item/268-adobe-creative-suite-toolbar-shortcut-w allpapers-exclusive
Thanks for the feedback, Alec.
I like the idea of a desktop image. And you make a good point about constantly looking down on the keyboard, rather than learning the shortcuts. I think it would work to train me, however.
Also, I tend to be in InDesign in spurts -- I'll work on a few projects for a month or six weeks, then I'll be mainly in other applications for a few months before coming back to InDesign. That's been a challenge for learning shortcuts.
As for the keys getting old: the idea is that I would set up my second (backup) keyboard as my designated InDesign keyboard, with the stickers; basically, I would only use it while I'm in InDesign, and use a standard keyboard the rest of the time.
Thanks for the tips, though. I would still like to hear from anyone who is using the stickers, if such users exist (surely some do!?!).
I don't know anyone personally who uses the stickers for InDesign, but I do know a lot of people who use them for video editing. It might be a good idea to go poking around in the Premiere Pro forum to see if anyone there has anything to say.