Good tips here!
Re: the map: If you can, print out a Google Earth satellite shot of the area, and make notes on that.
Re: a partner: FRS radios work well too and add to the safety factor.
Also, if you hunt in private land, don't forget to ask the LANDOWNERS about deer movement. It's their land, and if they're farmers / ranchers, it's a good bet they know it intimately. I have been astounded how helpful my brother's new father-in-law has been (and how much he las learned from us) about deer activity, deer trails, deer bedding areas, deers' senses, etc.. This guy has 8 monstor muleys that have been on his land for several years. He has saved them just for us, and knows their habits and the extent of their range very well.