I get a few private messages here and there on how to use NFP, so I figured I do a little post with "starter supplies" this way I can send people this link rather than writing up lengthy replies. First, this free app! It's terrific. No more paper charts and memorization. It sends reminders and is simple to use. If you take anything away from this post, this is the most valuable. You can even customize to use the app to conceive or postpone a baby.
This thermometer is great for daily use. I lost the one we had for 6 years while on vacation.
Finally, this textbook is great for beginners. Of course, you should always enroll in classes to know that you are using the method correctly. You can find classes here.
Love for others to share resources they have found for NFP! NFP can be used both to plan a baby or postpone, so either type of resource would be great :)