I read and take advice from a wide array of sources. I am, for example, a subscriber to
Jerry Pournelle. Jerry is a Goldwater Republican (literally, he campaigned for the guy), and worked for Reagan on Strategic Defense (AKA "Star Wars"). He's not convinced that global warming is being accelerated by man's CO2 emissions, which is not my position.
I also read
Making Light, the blog of the Nielson Haydens. That's the kind of hard-left place where a commenter will say "Bush should be charged with war crimes" and get 3 "amens" from other commenters. I don't agree with that sentiment.
On the other hand, sometimes both sites say stuff I agree with. Pournelle is frequently right in his analysis of the costs of the war (which he opposed), and the folks at Making Light are experts in the field of science fiction. And frequently, when these sites have posts I disagree with, I ignore the post instead of argue with them.
So, why do I read stuff written by people I disagree with? Three reasons.
1) Anti-Demonization. Reading and getting advice from "the other side" on an issue prevents you from demonizing them. You realize that they are people too, who just happen to be wrong on an issue.
2) Amen Choirs. Reading stuff you disagree with forces you to come up with a better defense of your opinion. "Because I say so" works with 5-year-olds, but not so well with adults. Exposing your arguments to the tender mercies of your opponents means that you opinions are better crafted and defended.
3) (Lack of) Infallibility. I'm not perfect, and neither are you, Dear Reader. Every once in a while, listening to the other side will allow one to learn something new, or correct an error in one's thinking. Some of the worst disasters in history were a result of group-think, where what "everybody knew" to be true wasn't.
Keeping an open mind is a great advantage in a complex world. I highly recommend it.