I'm sure they would welcome your support. Before you get involved with any rescue group or animal shelter, no matter if actively as a volunteer or contributing money, be sure that you check them out thoroughly. You need to be sure that you agree with their policies, the way they are housing their animals and the way the animals are treated. Please visit them before you write that check. Any reputable rescue group will welcome your interest in their organization.
Animal rescue can be very emotional and physically demanding.
There are lots of ways to get involved and as a reward you will know that you have helped give an abandoned animal a second chance for a happier life.