You can choose how the event will repeat in within each month.

On the same day of each month
If this is selected, the event will occur only once a month, on the same day (or range of days). Most of the events that follow this kind of pattern are holidays.
On the same weekday
Most meetings follow this type of pattern. Events can be scheduled to occur on every week of the month, or on certain weeks.

Once Again, use the "Preview Dates" button!

Note--Some events occur on more than one week of every month (the first and third week, for instance). This type of pattern cannot be selected, but can be created by adding the event twice--once for the first week and once for third week, for the above example. Of course, then you have two event series instead of just one...