I have been learning a lot as I manage and tie together the various social media sites. There is a site you should start with. It is http://en.gravatar.com/
This site let’s you associate various avatar icons to various email addresses you use. This can be any image you like to use for your photo on social sites.
Make yourself a login. Add any email addresses you use for sites like Disqus, wordpress etc. You may not even realize all the sites that accept gravatar managed icons. Then when you have an account at supporting sites with the same email addresses your profile pic will come from gravatar. This makes it much easier to make Changes to your profile pic across sites later.