Another concern

This is an addition to the previous post. I think I have been concerned a bit too much with teaching thing. I need to worry more about my own business, i mean, my research topic. To be honest, I find it quite difficult to set a concerete goal at this stage of my three-year research. But I know, I'd better have one. I would like to ask some help from those who are (or used to be) working on a long-term project. What kind of goal did you set for yourself at the beginning of the project? What did you learn from your project management? Do you have any advice at all?