I use software at www.Growveg.com to keep records of what I'm up to and to plan for the future.
It is very easy to use. However it is a paid for thing. I think you can still get a trial month free.
First time I signed up for it I drew my plans in the trial period and printed them out, but didn't sign up.

Forgot about the thing for a couple of years and then decided to sign up & pay up for real. Guess what they still had my old plans! I was well impressed.
So worth a look anyway.