Update a profile picture

I have this website (social network) where user can register, choose your preferences, favorites and interact with the website. But they can´t update a profile picture, just an icon according to them profile. So, that´s what a need: an option where the users can upload a profile picture with certain limitation of KB, and change anytime they want. This picture will be displayed always together with their names replacing the actual profile icon (in two different sizes generated automatically). I need a professional coder (or company) experienced on ASP and social network.