Welcome aboard! The mops are in the corner...

Seriously though, great first map - good color, interesting design. The layout seems good to me too - deserts, mountains, jungles all seem appropriate. I'm not much of a river policeman so I can't comment on their plausibility.

You said you made this in Artrage. I'm not familiar with the program, but I did notice around the mountains (and lakes and desert) there is a pretty strong noise filter of some kind. You might want to consider easing that with an overlay of some kind or a light gauze blur

I think the larger bodies of water could use some colors to note the depth, but that might just be my own proclivity.

Great first post overall!