When looking at how to learn speed reading, you should consider that there are several such techniques, each adapted to a different purpose and different style of reader.
As you may know, there are various programs that promise to teach you how to learn speed reading, both online and offline. Most are probably good, but you will need to apply yourself to the task and to exercise whenever possible.
In brief, the point is not so much about how to learn speed reading, but how to get rid of poor habits that were taught to you in elementary school.
When you learnt reading, your speed settled at about 250 wpm, because that was how much a child's brain is able to take in. In adulthood, your brain is able to process 500 wpm, but your reading skills have not improved - meaning that your brain is now free to think about something else while reading, and thus to lose interest and focus on the respective text.
Many people think they should not learn how to speed read, because they can't remember what they are reading at the normal pace anyway. In fact, speed reading is about saving some time as well as taking in more of what you read. The golden rule of speed reading is to constantly re-evaluate what you are reading, and never to pass by a word or a concept that you do not understand.
There are many things that slow down your reading: an improper environment with many distractions, a turned on radio or television set, the attempt to vocalize the words in your brain (it takes longer to vocalize than the actual time needed to understand them), the speed at which your eyes can move on the sheet to follow the words, or poor reading patters (for instance, the habit of skipping lines while reading, turning back to read some lines again, and so on). Identifying these problems will help your speed increase considerably, because you can address each of them separately.
One very easy way to read faster is simply to push the speed ahead, to switch into a higher gear, without putting too much accent on motivation or concentration.
In order to do that, you need to use your finger, or a pen (or the mouse pointer, if you are doing the exercise on the computer) as an index, to follow the words you are reading.
Start at your normal reading speed and then gradually increase it, simply by moving the index faster. You will see that the brain adjusts easily, and you can still understand everything you are reading.
