Budgets and budgeting does not have to be a mysterious or intimidating thing.

1. Take a small notebook with you wherever you go. The reason for this will become apparent. Get into the habit of getting a receipt for everything you can. When you can't get a receipt put it in your notebook. This includes everything, even a piece of bubble gum. Do this for a minimum of 30 days. Longer would be better, 2 or 3 months will give you a true look at your spending patterns.
2. After completing step 1 look closely at your recorded data. Make up categories for all of your purchases. i.e.: mortgage/rent, food, clothing, etc. Differentiate Fixed Expenses and Variable Expenses. Fixed expenses are those that do not change i.e.: house/rent payment, insurance, cable, etc. Variable expenses are those that vary depending on you or conditions, these are the ones where you have the greatest degree of control, they would include groceries, entertainment, phone, heat, lights, etc.
3. Add up all the expenses in each category.
4. Add up your income for the month. Add up all of the fixed expenses. Subtract the fixed expenses from the income. The result is what you have for variable expenses.
5. The leftover monies can now be spread over the variable expense categories. You now have a budget.