Create new crystal report with summary totals

I need to create a new crystal report that works with visual studio 2010. I need to have summary amounts at 2 group levels and at 1 final summary amount. I want the final summary amount to be in the report footer. I am asking this question since this is the first time will be writing a crystal report. Thus can you tell me the following:

1. How to you set up groups and come up with a summary amount at each group level?

2. How do you come up with a final summary amount for the report that is probably placed in the report footer? Do I use a regular sum, running total amount, section?

Thus can you tell me how to setup these summary amounts at the group and final total sections?