I've covered this subject before, both from the angle of what to think about before starting a business with a friend and from the point of view of splitting shares, equitably or not, and even ways to not split equity at all.
Stepping earlier into the process, before you start a business with someone, what are those key questions you should ask each other? Here's Charlie O'Donnell's list of questions to ask before you start.
That being said, some of the questions seem a bit too early. It may be worth touching on things like equity split for employees or company values before you even have a shred of a business going, but getting bogged down in those questions would be disastrous. Spend an afternoon chatting about them, but no more. If you're getting started, get started.