Hello Vita - and welcome!
I am not the right person to answer your question about the e-book - it gets good reviews, so I guess many people find it useful. Personally, I learn best by trial and error and playing around with my camera. I have had the K-10, K7, K5 and now K3, and I confess I never completely finished any single one of the official manuals for those.
I do ask a lot of forum questions though, and I have learned more about camera settings and creative possibilities by reading forum posts and asking forum questions than I think any manual could have taught me.
But - I am sure you will get an answer from someone who actually bought and read the e-book! This post was just to say welcome.