The booklet 101 Tips For Better Officiating, by Referee Mag. concludes with Chap. 10 titled: How to Master Any Sport's Rulebook.
It lists 10 tips: 1) Speed-read entire book. 2) Categorize the rules. 3) Chapter breakdown. 4) Create a quiz. 5) Have several copies of the same rulebook. 6) Read in short increments of time. 7) Review the book each day. 8) Study just before falling asleep. 9) Check related casebook plays. 10) Talk with rules experts. Of course they went into a bit of detail on each one of these topics. I found most of them very helpful.
You can order that booklet along with some other pretty good stuff from NASO at their website,
http://www.naso.org.