there is gas stations along the tracks all day. you need capacity to go 90 miles between gas stops.
buy a roll chart holder. info on page 1. it's not hard to use, just make sure your ODO works and have a Garmin GPS.
no need for past tracks. it's desert riding. mostly 2 track and power line roads. some single track on the "hard routes" which are voluntary and will join up with the regular route. and the tracks change every year.
be advised that there is a lot of sand. it's the desert.
and rocks. again, it's the desert.
it will be cold at 6AM. last year it was 40, the year before it was 25. daytime temps can be in the 80's but probably most likely the mid 60's to mid 70's.
dress in layers and think about installing heated grips. buy a balaclava, winter gloves, and maybe a skull cap.
in the 5 years I've done this ride, it has not rained, but is a possibility. have a rain pullover ready or pack a trash bag. and some guys wear rubber surgical gloves under their moto gloves to hold in the heat on cold mornings.
go to the District 37 forum and download the entry page. it has other info in it for you.