Based mostly on how real world science would have it*, I give to you a map with ocean currents, with thickness of arrows being a rough estimate of how intense the currents are. It assumes the equator is either at or just below the bottom of the map.
*The Part not exactly based on Science are the arrows on the far left and right, but I added those in because I imagine that we don't want ridiculously hard trade against currents. Plus it's fantasy, so its allowed to have a little freedom, right? Anyways, the map is below.

[hider=Map]
[IMG]http://i.imgur.com/btVuAtG.jpg[/IMG][/hider]

I'll try to get one with wind patterns up soon.