Have you ever heard about syncfusion? It has lots of free resources on different kinds of technologies and famous programming languages. I've read several books of this publication such as JavaScript, TypeScript, Knockoutjs, Unit test, jQuery and F#.
they are free and averaging around 100 pages. Most of the time you don't need to read a reference book about 1500 pages to learn something! If you want to jump start over any programming language, framework or technology, trust to all of this publication's books. I've got all of the free e-books of syncfusion and definitely want to read them.
You can get the free e-books of syncfusion here, I recommend you to get these e-books based on your fields of skill as they are free and full of useful contents written by experienced people. I hope that syncfusion publish more books on various fields such as NoSQL databases, architecture, patterns and ...
finally thanks for Jennifer on the marketing team at Syncfusion for designing the above image for me, I've read all of the books in the image! cheers...