Here's a couple of good articles I found on how to learn more quickly and efficiently:
How to Learn More and Study Less | Zen Habits Hacking Knowledge: 77 Ways to Learn Faster, Deeper, and Better | OEDb
I would also add, that you should keep in mind the difference between learning necessary and unnecessary information. Sometimes the best way to learn can be to restrict your input so that you are able to remember the important things. Also, simply because you started a book, or an article, doesn't mean you have to finish it if you're not finding any real value. I think we often get into the habit of trying to finish something just so we don't feel guilty.