There are probably many ways to do this however, a very simple method would be to use the Data Sort feature.
Enter your data ( Name, Address, AmountA-C) in columns B-F. Once you have all your Data in return to COlumn A next to your first Entry. Type in the number 1. If you have a large number of entries you can Highlight the Number 1 in Column A and then highlight all the remaining Cells next to where your data appears. Click on Edit | Fill |Series and click OK. Now next to your friends names the numbers will appear from 1 - however many entries you have. These numbers will be highlighted so click on Copy. Go to the last Entry and select the row right below it and then click on Paste. Now the series of numbers will appear once next to your data and a second time next to blank rows. Now select all the data, ( With the Cursor next to the First Entry in Column A, Hold down the Shift Key and hit the END key. This will select all the data in the sheet. Next Click on Data | Sort and click OK. All the data will now be separated by a blank Row.
Your Sum Formula will always work if you set it up a Row below your last line of data. If you add additional data be sure to do it above the Total formula and it will always work.