I have the People’s Desk Reference on Essential Oils but I also really love this phone app to help me look things up even if I’m out and about and need help or to help someone else. I also have a guide at home for using oils safely on pets too, because my house is like the Castle Kingdom! LOL I tend to rescue everything needing help. 🙂
http://play.google.com/store/apps/details?id=com.healthcare.essentialoilguide