know in 3 hours? Is it worth the money or should I spend it on a book? If the book is the better option, which one would you recommend?

If you have done a lot of digitising you MIGHT learn a lot in 3 hrs as the principles are the same, it's the settings you want to know. And how to make your own stitches in user editors. You can learn that in a short time. After that it's experimenting and test stitching on your own - great fun, frustrating at times when your tests unravel after washing, and highly rewarding when you succeed.
So it's really a matter of what they teach you and how fast a learner you are.

Three hours???? Hardly. More like 3 years. LOL!!!
You could probably learn how to digitise one single design in three hours.

But are they offering to teach you how to MAKE FSL or how to DIGITISE FSL???

There is quite a difference and I would clarify that with them beforehand or you might pay your money and be disappointed.

Digitising is time consuming and learning intensive, how quickly your learn and how proficient you become all depends on your own personal ability to absorb and remember the information and be able to put it into practice when you don't have the teacher standing nearby to remind you what to do next.

Depending on the digitising program you have, the best thing you can do is join a yahoo group for that software and ask the question, who has the best tutorials for my program.
Hope this helps, hugs n roses, Meganne