Greenmount Cemetery is one of the large cemeteries to the Northeast of Rising Sun. (Green Mount is another, incorrect, spelling)
Records for Rising Sun ME could be at the Historical Society of Pennsylvania or at Old St. George's Methodist Church at 4th and New Sts., Philadelphia.
Obtain a paper map of Philadelphia from your local bookstore (Border's, Barnes and Noble, etc.) It will significantly help in locating sites such as cemeteries, churches, streets, etc.