What are the steps and fees ociated with applying to become a Non Profit Organization?

I belong to a small group of individuals that wishes to apply to become a non profit organization. Our group is growing rapidly and before it gets out of hand, we want to get the legalities worked out. We're unsure of the steps to take to get the ball rolling and are unsure of what fees will need to be paid to apply. Can someone explain the process and the costs to me?