you may find PDF guides on Qlik Help page:
It's actually the same material which you can find in Help, but in my opinion PDF version is easier to search any phrases.
Some time ago there was a free ebook available: Qlik Sense Cookbook, you can try to google it.
And I can recommend some blogs about QV and QS:
Have a nice reading
QlikView 11.2 (and earlier versions) came with a manual in PDF on install.
QlikView 12.x and all versions of Qlik Sense have made the transition to online help.
To find this online help, go here:
The QlikView Guides appear to have everything that appears in the reference manuals and more and it is up to date:
The "script syntax and chart functions chapter" (chapter 11) in the "Working with QlikView" guide is where I've found most relevant references to functions and syntax. I've been using this guide as it has useful documentation concerning functionality that I am not familiar with (I'm a QlikView Engineer in Training).
Also, this community is fantastic as well. There are a lot of very knowledgeable experts here answering questions all the time.