Cleaning + chemistry: Where do you find your reliable DIY cleaner recipes?

I've seen all the usual DIY eco-friendly cleaning recipes floating around the great wide Interwebs, and tried out most of them. But I'm wondering… are they all really safe? For example, I'm kind of suspicious of the baking soda, vinegar, and castile soap chemical reaction that takes place. What are some reliable resources with DIY cleaning recipes that rely on real research about the actual safety and effectiveness of the recipes?


Vacuum out your heat ducts right now

This past spring (or the winter that would not quit here in Minnesota) we noticed that our heat seemed to not be working so well. My head immediately jumped to how to find a furnace repair person and how much that would cost. My wife suggested we try vacuuming out the ducts. A bit of internet research has shown that apparently you're supposed to do this on a regular basis, but I had never thought to do it before. So now you know!