Reading

Posting my process because this is what I've found works for me, but think it varies person to person and you'll figure out what works best for you. 

1. Get into the habit of reading first: When I started trying to read some dense investing books, I found that I was struggling to concentrate on what I was reading and my sporadic reading (like read a chapter, don't pick up the book for a couple of days, then try to pick it back up) made it hard to remember anything I read. I think this was because I just didn't really read many books. What I found best for me was to ease into reading with books I found fun / didn't want to put down to get me into the habit of reading. Books that made me want to read everyday and replace other forms of entertainment (TV / video games / etc.). For me these books were the genre defining books of fantasy / scifi / lit fiction. Once I got into a really good habit of reading I started to slowly incorporate non-fiction (business bios) then the high level / entertaining investment books ("margin of safety" and "you can be a stock market genius" I think are great first books) then finally got to the more advance level stuff.
2. Think about what you read!: A major difference between  "fun" books and "learning" books is that you can read the fun books fast most of the time without thinking too hard. For what you describe as the "textbooks" - I typically only read one chapter at a time, take notes on my phone, try to think of the major concepts of the chapter I just read, and how I could apply them. I also would try to apply what you read as soon as you could. Like if I just read Michael Mauboussin's paper on measuring the moat, I would go and try to do that. This seriously makes reading slower, but you really do achieve better apprehension and it will stick with you longer.
3. Enjoy the journey, not the end result: A lot of us are achievement hunters and that shows in our reading. Don't rush through a book because you want to say that you've read x book or y amount of books. Saying you have read a certain book really gets you nothing if you don't remember what you read and you haven't learned something from it. Learn to enjoy the process.