Read through the assigned reading as quickly as possible. (Speed-read if you can). Don’t take any notes, just catch the highlights or overall concept of what you’re reading. The first reading should take much less than half of the time it would normally take you to read through the assigned reading. If not, speed it up!
On the second read-through, read the assignment more slowly and take notes. Specifically slow down on the more complex portions and try to get a grasp, but your overall speed should still remain well above your typical reading speed.
Finally, read through the assignment a third time. All told, you try to keep the total time spent very close to what you would have spent reading it in a typical setting.
I’ve used this method several times and it works very well for material that you want to hold on to. The point of the exercise is that you have seen the material 3 times instead of one. The first reading also helps qualify the second and third passes with a better idea of the overall picture. However, this method takes discipline and if you don’t make a conscious effort to read fast, you can spend much more time than you normally would reading.