I have developed an Excel sheet that shows how to preform project scheduling using PERT. You can modify it to accommodate your project. You can download it from here. To learn more about the steps of generating schedules using PERT click here. It should be noted that in this example, the finish to start relationship is used in this Excel file. The Excel workbook was developed using the 2010 version. If you are using MS Excel 2007, you need to do this small modification. In the Schedule! sheet, the functions in cell J7 and N10 should be changed to NORMDIST and NORMINV respectively.
If you have any questions, please do not hesitate to ask.