Environmental scanning (also known as horizon scanning) is part of anticipating the future. It's done by systematically gathering information about current and changing conditions. Good foresight requires environmental scanning for understanding emerging change.
How do you scan the scanners?
Find the bloggers, news sites, podcasts, etc. that cover the range of news and information you need to monitor. Online sources, including tons of free ones, do this work well. You can fine-tune what you look at to tap well-curated sources.
My interests flop all over the place, and I find value in a rich mix of places. It's an ever-changing landscape of sources, but some I find valuable these days are: Reddit Futurology, PSFK, Slinking Toward Retirement, Boing Boing, and various of my savvy friends' twitter feeds.
My colleagues are scanners who curate insights with a focus on the Future of Packaging on Twitter at @packfutur, and on the future of work at @50PlusatWork on Twitter and the Future of Work on Facebook.
Your best strategy is to find a manageable set of sources. "Automate" your monitoring by subscribing to email newsletters, using social media, or RSS feeds. That means information will flow to you. You won't have to remember to check multiple sources.
Keep fine-tuning your set of sources. Ditch anything that wastes your time. Add sources when you have a particular focus or project.
One caution. You can be too tailored in your strategy. Allow in some variety, alternative views, and serendipity. You will make discoveries that way, instead of allowing confirmation bias to get ahold of you.