One of the best resources for anyone Pregnant, Breast Feeding, or Trying to Conceive as far as medications go is Safe Fetus. My mom is a nurse, and even she was impressed by their comprehensive look at different drugs effects. To give you an idea how this works.. here is what it has to say about Advil. I love how it breaks it down into different categories... "B" for 1st & 2nd trimester of pregnancy.. "D" for third Trimester, Also telling you what the fetal risk is when used, and then whether or not it passes into breast milk. I turned to this website many times, and have referred other Mama's to it as well.
A good website for child safety, recalls, and general health and wellbeing is Safe Mama. (I'm especially interested right now in coming back and reading her articles on Sunscreen and Bug Repellents.)