I am a first generation hunter and pretty much self taught. So, this not only being my first mule deer hunt but my first rifle hunt is there anything you wish you could have known for your first few rifle mule deer hunts?
I am just like you. Nobody in my family hunted and I have bow hunted until two years ago when I got a rifle mule deer tag because my wife wanted to start hunting so I thought I would give it a go on my own before she joined. I had a third season buck tag, and it was in a unit that I have bow hunted for a decade or so.
I learned that the first thing you need is patience. I saw the back end of one buck exactly where I thought one should be after glassing the little 1/2 acre spot for 15 min from a few hundred yards away. I wanted to crest the hill on the opposite side of the little spot and was confident it was animal-less. I was wrong.
I found a good amount of bighorns around the highest part of the unit )10500'), but no deer. I found no deer mid elevation, I found bighorns in the lowest part of the unit (6000') and never found a deer glassing, or any sign that was encouraging. I was walking back to my truck in the afternoon and out of the corner of my eye I saw something standing on a rock. It turned out to be the dumb deer in the area about 300 yards away.
He stood there long enough for me to take some pictures, get settled on my pack and bipod in the dry creek bed, and I even unloaded and dry fired a couple times to confirm my comfort. He never moved so I shot him. The walk up that hill was very thick and steep, and took a whole lot longer than a normal 300 yards.
So, I learned to be patient and to understand that my purpose was to learn. I also think that after having hunted the same area for deer and elk with my wife this past season, that a mule deer buck is pretty darned content in not moving when they think they are in a safe spot. I ended up finding a few other dozen deer in the sand bottoms in the dark, but I didn't bump any around during the day at all.
The above post about winter range, migration routes (if one occurs), roads, and glassing points is spot on. If you can figure out how to get to where you want to be easily AND how to observe it without disturbing it, you can eliminate possible places. My experience was opposite of the typical find does, or hunt in X elevation until it snows, then Y after that. I think the biggest thing that I have learned after being out in the past two rifle seasons, is that second guessing my own instincts that I developed bow hunting and trying to fit my hunting into a cookie cutter might be the biggest detriment.