Nice map, Slade!
Here are my 2 cents -
For me, I would make the world you want to create drive the map rather than vice versa. At the end of the day, the purpose of the map is to be used to portray the world in which the players will be adventuring, so flesh out (roughly at least) what sort of world you want your players to adventure in. Some considerations to take into account are:
And so on.
- Urbanisation / Wilderness Ratios.
- Key Locations - be they cities or natural features.
- Climate - Is it earthlike, is the north cold and the equator humid?
- Cultural classifications / technology- if your world is more of a rennaisance type one would expect more urbanisation than medieval and the ratio to be higher. Cities are likely to be larger and so on.
- National Borders - these often follow natural boundaries like rivers or mountain ranges.
- Roads - Higher the technology level the more one would expect.
Once you have a rough idea of these elements the geography becomes easier to plot and hopefully you will not have any 'gaps'. E.g. not putting in a desert where you anticipate one might be required at some point. Of course once you start plotting the map, other adventure ideas may come to you as a result so the process is an interacive one.
For geographical features, the best rule for comparison I find is to take a map of the earth (or part of it) at a similar scale and see how it compares to what you've drawn - your world is about 1/3 of the earth's circumferance if the map you have drawn 'wraps around' East-West. See if, at least it looks sort of like a real world map in terms of general placement and then you know your map will look natural to the players. No need to follow rules slavishly though as this is fantasy. Of course there may be some 'cause' e.g. a magical rift in space etc. which might alter the geography radically from that of earth, and then you would have to think about what the knock-on effects of that would be.
There are some good world building manuals. Check out the Reference Material and Tutorial sections of the site which contain some good links to world building tutorials / essays.
For example look here and here also take a look at 'conworlds' in wikipedia and the links at the bottom.
Hope this helps!