I feel this is the most important part of keeping your personal finances in order. The best way that I can think of to put together a budget is through Excel. The way I do it is I low ball the income (not by a lot, but by a few bucs), and high ball the expenses, this way if you stick to the budget you'll have some money left over. Also, another way that I find it easier to save money is to actually work it into your budget, don't just put whatever money over you have left into savings, actually figure our how much you want to put away each month or week, and work that into the budget.
You can do whatever you want with this money, put it away for a vacation fund, put it into a high interest bearing savings account until you know what you want to do with it.
I read on another blog recently about how you dont want to kill yourself saving and saving for retirement, you are working, so you want to be able to get out there and enjoy some of the money you are making. If you can put together a solid budget, low balling the income and high balling the expenses, that is the first major part of getting onto the road of financial stability.