http://www.helpersoftheholysouls.com/

The mission of Helpers of the Holy Souls is to relieve and gain release for the suffering souls in Purgatory who can no longer help themselves. Their primary aim is to have Masses, said by selected priests, every day of the year for the Holy Souls. Their secondary aim is share their apostolate with others who have a desire to replicate what they are doing. They accomplish this mission by holding monthly collections used solely to have Masses said for the Holy Souls and by having prayer meetings. The secondary aim is to share their apostolate with others who have a desire to replicate what they are doing.

The website is well done and a very good place to learn more about the souls in Purgatory and how to help them.

From Catholic Culture.