Here are the basic mechanics: http://paulgraham.com/equity.html http://paulgraham.com/equity.html EDIT: The only other thing I can think of is that you need to

Here are the basic mechanics: http://paulgraham.com/equity.html http://paulgraham.com/equity.html EDIT: The only other thing I can think of is that you need to make sure you're equally protected against dilution (like what happened to Eduardo Saverin), I don't really know how this usually works.