Some suggestions:

• Read How to Read a Book and implementing as many of the suggestions as possible. It's working well for me, particularly the act of writing out summaries in my own words.
• Chronological order. This stopped me from being overwhelmed by the number of tabs opened in my browser. Whenever I click on a link I think, "Oh yeah, I remember reading this," and can continue with the original reading.
• Mind mapping for comprehension and retention.