Mini-goals are great and really do help you break things down into ideas that are more manageable. I know I would have been intimidated if I had set losing 100 pounds as my first goal. And yet... I'm almost there. A wise fellow 3fc'er who began at around 600 pounds has said that she can't lose 100 pounds, but she can lose 1 pound 100 times.
That being said, I actually try not to set time deadlines on weight loss. What if you do things right and still don't make it. Sadly, our bodies don't lose weight at the rate we would like, even when we behave.
Instead, I focus on behaviors... am I meeting my eating and exercise goals? I find that focusing on the behaviors I can control, while still setting weight loss goals, has been very helpful!
My 5 C's of healthy living: Commitment to conscious control, with the understanding that choices have consequences