It's important to know what kills them, to recognize their patterns. Ask yourself simple questions such as "Can they break down that door I just barred?" and "Will they walk around mindlessly if I happen to strand myself among them, or will they ravenously hunt me down until I'm nothing but a pile of broken and severed bones?"
In Shaun of the Dead we are taught how to mimic the walking dead so as to evade them whenever we need to. Of course, this may not always work but it's worth a try - if you've studied your zombie's characteristics proficiently, that is.
You'll need someone like Ben (Duane Jones) from Night of the Living Dead to lead your group because he's resourceful and hell-bent on surviving this zombie apocalypse - unless you're already a natural born leader, of course.
Kenneth and Michael from the 2004 remake Dawn of the Dead are also good choices but I think everyone agrees that one leader is enough.
Remember to listen to the leader in your group. Ten in one he's right. And it saves everyone else from too much tension during this already tense time.