Hi Melissa,
Making a budget is fairly straightforward; sticking to it is not. You may want to consider taking a month to do some research. Keep a journal of everything you spend money on and how much. Include things like the biggies--food, rent/mortgage, gasoline--as well as the fun stuff--movies, books, fast food, etc. At the end of a month, evealuate your spending. What was food running you, on average, for a week? How much did you spend on fast food?
Next, look at your income vs. your expenses. Ideally, you should be spending less than you make. If you're not, and using credit to buy stuff, you should consider cutting back on your expenses so you can live within your means and save a little each month. The goal should be living as debt-free as possible.
The most important rule in making a budget is being realistic. My food budget stands at $150/week for a family of four. We eat simply...no soda, no cookies or candy, lots of fresh fruits and vegetables. Some weeks I'm over, some I'm under, but it all works out by the end of the month. Pad this budget item a bit to cover any seasonal fluctuations. Same for gasoline. Track how much you spend and plan accordingly. For my family, it's one tank per week per vehicle. Pad this a bit, too, to cover any unexpected trips. Take a look at where you sepnd your "extra" money. Are you spending $20 a week at fast food? Dining out? For me, the killer is the bookstore. I could spend $50 a week on new books!
Once you've evaluated everything, make a list of money spent, cutting where you need to so you live within your means. This is the surprising part, where you can save money and where you can't. For my family, this process has led to new, more feul efficient cars, and once, a new, less expensive house. With the tough economic times, we've had to cut back on driving to be able to afford food. The AC is set higher, the heater in winter is set lower. We cut back on water use in the yard. The list is endless and sometimes depressing.
But, we're realistic. We didn't cut fast food out entirely, knowing there would be times when that's the best option for dinner on a busy night. But, we did try to find quick easy meals at home. Is the budget perfect? No. But, I have a very good idea of how much I spend each month and where I spend my money.
It's a discipline. Watching your savings grow is often a great motivator. Watching your credit card debt disappear is better. But, if you can master this discipline, life will be much less stressful.
I hope this all made sense. I teach a personal finance class to high schoolers, so it's a subject I know well, if not always practice!
Good luck!