You will need between 2-5 pads a day, depending on how often you like to change your pad, how heavy your flow is and how absorbent your pads are.
It is recommended to have at least 6-12 pads... I personally think 20 is a good sized stash. The more you have the less wear & tear on each pad, making them last longer. This might seem like a lot of expense to begin with, but they will soon pay for themselves in savings. And you may find it fun to collect pads, having different colours and styles just like you would clothing choices.
It is best to make sure you have several days supply in case you are not able to get them washed and dry in time. You can add to your cloth pad collection as time goes by, buying a few now and then to spread the expense and wear and tear on your pads.
Some guidelines here:
Medium size - suitable for teenagers
Large Size - suitable for mothers
