Here is a collection of free ebooks for the Holiday Season!

1.

A large collection of free eBooks from Microsoft Press (PDF, EPUB and Mobi for Kindle formats)

https://mva.microsoft.com/ebooks

2.

Also do not forget the very nice “Succinctly” collection from Syncfusion: 80+ e-books on popular technologies with all the essential content in about 100 pages.… for free!

https://www.syncfusion.com/resources/techportal/ebooks/

Personally I will definitely take some time to read this: TypeScript Succinctly