i don't trust anyone, not in the sense that you're asking. i don't think that any author or expert is going to be a reliable source of information and advice 100% of the time. i'm kind of skeptical of parenting books anyway... i mean, i've read bits and pieces of lots of books dealing with pregnancy, birth, babyhood, parenting, etc, but so far i haven't found that anyone has said anything that i didn't already know instinctively, or said something that made sense immediately followed by something i thought was a bit off. especially in the areas of sleep and food, i think there is a huge market for "experts" because they are two things our parenting culture is obsessed with.
My oldest is 18 so I saw the whole "attachment parenting" movement rise in books and on the internet.
I love the attachment parenting ideals and liked to be able to discuss them with La Leche League friends and on the internet, but when one of the internet moms wrote a book on Attachment Parenting I was disgusted. It's about reading your baby's cues, paying attention, being involved, trusting yourself, and all of a sudden there were moms saying they were "attachment parenting" so they had to do this or wouldn't dream of doing that. It was infuriating.
Not that books can't be helpful - I read a lot of them and some were useful. Sometimes it is nice to have an expert with a book backing up your philosophy when family members are opposed to how you are raising your child, and reading the book may help them understand your parenting/feeding.