Thinning out curly hair?

I'm growing my hair long so I can have it donated to a charity. However, my hair's getting quite thick around my ears and it's driving me nuts. How should I cut it to make it less thick? I'm afraid that just cutting the hair around my ears short is going to make the rest of it poofy. I have 3b hair.
I like work. It fascinates me. I sit and look at it for hours.