[cycloptic]

Yes, there is. Selling books, seminars, and certifications is very common in the Linux world.

[Shared404]

But most of those are targeted to the IT side of things, aren't they?

I don't recall having seen much targeting end users.

[cycloptic]

It really depends on what you're looking for. I've found for popular applications there are usually tutorials on Youtube at the very least.