How to display total numbers in a report?

I created a form and added number of records. The problem I have is that the report shows each record separately. Is there a way and how would I create a report that would show the total for certain period of time.

For example:

I would like to keep track of all rentals I have made. I enter each rental into the form. In the end of the month I would like to print a report that would show total numbers from all entries in that certain period of time - like total rental amount for the month, total tax collected, total commission, etc.

Is there a way to do so and if so could you give me a little hint how to accomplish that?

Thank you so much!