nice beginning map ...
1. The river is basicly ok - however, both the river and the coastline are very thin in comparrison to your other elements - so I'd thicken them up some
2. A desert is basicly empty land - so dunes and an oasis is mostly what you can do to show it
4. Glacial land is hard to make - again like the desert you have mostly empty land - a key to your symbols can help this though.
with those questions answered - I like your texture and good colors, you'll get the hang of this in no time
for future uploads I would propose that you push the "go advanced" button and use the "attachment manager" to upload your pics directly to the guild - that way we're not dependent on another site to work to see the images in our forum
and for future works ... make a WIP thread as you work - that way you can get help while you work and not only after you're finished