1. Income and expenses
Yes, it's a most obvious one and yet so many of us put it off. But knowing how much and when you have money coming in and going out, is crucial - it's called cash flow. In addition, by tracking what you are spending your money on, you can look for ways to cut waste.
The program I use is Quicken Deluxe 2010. I sold a house once and when I entered the figures into Quicken, they didn't add up to my lawyers bill. Upon checking I discovered he had charged me twice for an item. Quicken saved me several hundred dollars on that one transaction!
Again another obvious one but it's surprising how many people don't pay attention to how they spend their time and on what. Read The One Minute Manager and learn how to better manage your time.
The greates money and time killer of all can be your habits. Good habits are the corner stone to better time management and greater financial stability. Stehen Covey's, The 7 Habits of Highly Effective People, is a classic in this field. His book was invaluable to me during my Navy career. I recommended it to my wife for her job and she put it off for years. Recently, at a work seminar, the book was suggested reading for the group. My wife said she wished she had listened to me all those years ago.