Water exercise really works well for me. Walking does too but I think it is important to walk on a supportive surface instead of pavement if you can. Also, SuperFeet makes good supports for shoes. My former physical therapist recommended them due to the arthritis in my feet and they do make a difference. They area about $30 for a pair but they are very durable and very supportive. Mine lasted me about 9 months! They make difference levels of supports but the bright green is for heavy walking, and a lot of shoe stores carry them. They are on the internet too I think.
Most of all, I think it is important to be gentle with oneself!