Very thorough write up of the basics. A few additional thoughts that occurred to me as I was reading:
1) think carefully what kind of map coordinate system you want to use. Lat/Long coordinate are great when you have a large scale map or are calculating travel over large distances. Other coordinate systems are UTM (universal transverse mercator) and MGRS (military grid reference system). Both of these function similarly, with the exception being that MGRS uses a alphanumeric code to identify the map sheet being used while UTM simply uses additional numbers. Either of these can be used with a protractor to find locations and azimuths more precisely. It can also be used to measure distances. While MGRS can be a little easier to read because the map sheet identifier is visually broken up from the point location, UTM maps are a little easier to find.
2) The relevance of the datum for a map has to do with the potential accuracy of coordinates. If coordinates were pulled from a map using a different datum, for example, they might not translate correctly.
3) When planing a route, it's often less of a headache to traverse the high ground as opposed to simple straight line of bearing. If you're traveling over undulating or mountainous terrain, travelling on a straight azimuth may result in a lot of up and down. When moving over the high ground you may go up farther, but that also means you can identify your next point a lot easier.
4) Try to avoid approaching hills or ridges from a draw and instead move up the spurs as your approach angle will likely be more consistent. Draws typically start out at a lower angle but end up a lot steeper as you approach the high ground.
5) In addition to orienting the map north, try to keep it oriented that way as you go along. In essence, each time your direction changes, turn the map as well. In essence you're orienting the map according to your direction of travel. That way, as you move you're able to navigate by terrain association and should make it easier to keep your bearings.
All that being said, I highly recommend the milGPS app as it'll let you pick your coordinate system, map datum, etc. It'll also allow you to enter waypoints and calculate route legs (distance/direction, etc).
