First, you don't actually have to read everything in a book or newspaper to understand it. In fact, it's impossible to read everything that passes over your desk. Instead, you should get in the habit of selecting and prioritizing what's actually important.
Second, you don't have to remember everything you read to get something from the material. We develop this misconception about reading in school, where we're under pressure to remember everything we read in our textbooks because we'll be tested on the material.
If you want to retain the information for the future, you'll need to create an easy retrieval system.
Try writing down the crucial information (electronically or on paper), or make highlights and notes in the margins. Then, simply file the materials away. This way you can find the information easily, and it will also take away the pressure of memorizing everything.