Personal Projects - What Questions Should I Answer?

The real challenge that i face in doing personal projects it coming up with the questions. What questions should i answer in the first? There's a bunch i can do, but i don't know exactly where to start. In this case, just make you the the question your asking is interesting to you. And then if you've got a bunch of questions, but you don't know which question to start with, i would say, write all the questions down and see if you can order the questions with numbers one, two, three.