You could try picking up a reading & comprehension test-prep book, like you would find for SAT/ACT, GRE, MCAT, etc and practice reading the passages fast and do

You could try picking up a reading & comprehension test-prep book, like you would find for SAT/ACT, GRE, MCAT, etc and practice reading the passages fast and doing some questions for comprehension. This way, you have concise material (500 - 800 word passages), that are complex in wording and ideas, and you can test yourself to see how much of the passage you understood. Reading fast is one thing and comprehension/retention of the material is another. Ideally, you would want to improve all three simultaneously. That's why I'm suggesting start off with smaller, more manageable passages and analyze your understanding as you progress. You may get every question wrong in the beginning, but don't let that bum you out. Keep doing a few passages every day and you should definitely see improvement. Once you build up a strong base, you can move onto articles, like you would find in The New Yorker for example, that can span several pages and are littered with more complex ideas and examples. You really won't be able to test yourself with questions at the end, but you can ask yourself general questions, like: "What was the main idea?" "What side did the author take?" (if the piece was argumentative in nature) "What were two examples that the author used to support their claim?" (again, if a claim was being made) Be honest with yourself, if you find it difficult to answer questions like these, read through the article again and go through it with a highlighter (sparingly, mind you). Also, you can write little notes in the margin to help you gather the content and your thoughts as you go along. I hope this helps and best of luck :)