Macbook Pro Fan

I'm typing on my Macbook Pro with only Safari open and logged in to this discussion page. I can hear the fan, running slow and almost silent. My MacBook Pro is cool to the touch. Is the constant fan operation normal? Also, relative to my Old PowerBook, I notice the MacBook Pro fully charged, seems to use more power when the book is closed, asleep, and then reopened hours later. Usually about 4 to 5% decrease in percentage. Is this within normal parameters as well?