Once you complete the FAFSA your Pell is automatically generated.
If you are a rising high school senior, apply for the Free Application for Federal Student Aid (FAFSA) at fafsa.gov soon after the updated form comes online January 1st, 2012. The FAFSA will qualify you for federal direct loans and grants (i.e. Pell and Federal Work-Study), and sometimes state aid, depending on your home state.