Here is an amazing website for all of the cooking questions you have ever had or ever wanted to know. I’ve used this website many times and today had questions about using melted butter vs softened butter in a cookie recipe and how it would change the recipe - I found my answer. Here are tips and the 911 on cookies:
http://www.baking911.com/cookies/101_tips.htm
Go to the home page and see all of the other categories they have to offer.