Pleasant is what you are, pleasing is what you do
I'd tend to use "pleasant" to describe something happening naturally - "a pleasant sunny day" or "a pleasant cheerful disposition", whereas "pleasing" is more the result of an action or something someone's done - for instance "a pleasing school report"
The pleasant breeze was pleasing to me. <br />
Pleasant is what it is. Pleasing is the results.
pleasant is what you feel for a moment but pleasing is what you feel forever