Well, if your landmass is about the size of Asia (circa 44M square kilometers), the Monsoon cycle would probably have a pretty significant effect. Actually, considering that your landmass is situated just north of the equatorial waters, I think the monsoon effect would be even dominant. Anyway, here's my suggestion for Summer winds (sorry if it's a bit rough, but you should get the idea):

winds_suggestion.jpg

Regarding rainfall the area covered by the summer Monsoon winds should rain a lot in summer, but be largely dry in winter (when the Monsoon effect reverses, and winds blow from land to ocean, being dry air). Your best bet is probably to look at India and southeastern Asia in general if you want the specific rainfall amounts.