Like Peppy2, we have an excel spreadsheet we made ourselves.
Essentially, it works on a day to day basis. The left hand column is each day's date, the rows at the top are Date, Transaction Description, Cash Movement, and then account balances.
We have it set up in four week blocks, with the weekends coloured differently, so it is easy to see where you are at. We input all regular income and outgoing expenses, such as my pay (weekly), DH's pay (fortnightly), credit card bill (we pay all other bills on our credit card, amount inputted to table is predicted based on our average spend), mortgage repayment. These are set up as recurring transactions, so you can predict your bank balance months in advance. As you get more information you can adjust your outgoings (for example, our billing month for the CC ends on the 11th, and is not due to be paid until the 26th, so leading up to the 11th we monitor the balance and adjust spreadsheet accordingly. By predicting your income and outgoing expenses it helps you to know where you're at, and whether you're actually going to have enough income to pay your mortgage next month, and how much spare you've got to play with. If you're good with excel it is easy to set up.
We balance our budget weekly with our bank accounts, making sure the account balances are accurate, and entering interest, and any cash withdrawls as you go. As each week is balanced we change the colour so we know it is correct.
My DH, the financial guru of the family, set it all up.