Currently, it's around 75 books. It used to be over 200, but I realized there are only certain books that I will actually read, so I narrowed it down.
A majority of these books have already been released, and there are some that I'm just waiting to be released (and of course there are some that I want to read but don't know when they are going to come out).
If you haven't read Ready Player One then it's a good sci-fi / young adult book.
There is also Ready Player Two after you finish that one.
Cory Doctorow also released a new sci-fi book recently, called Red Team Blues, which you may be interested in.