The first step in planning spending is to know how much is coming in and how much is going out. Some people call this a budget, others cash flow. But whatever the name you use, a budget will let you plan and know where your money goes.
For example, you can set aside the money necessary for savings, paying the rent, buying groceries and paying utilities. Subtract those necessities from your income and then you know how much you have left to spend on other things.
The following resources may assist you in creating a budget: