Here is a rough list of what needs to be done and when. Of course, everyone is going to have a different amount of time between the engagement and the marriage, so you'll have to work out a schedule of your own based on these guidelines.
12 months +
9-11 months
6-8 months
4-5 months
2-3 months
5-6 weeks
3-4 weeks
1-2 weeks
Day Before
Day Of