I began painting in February 2006, at age 73 (I was diagnosed with Parkinson's in July 2001.) I have completed 82 paintings with acrylic through January 2008, most of them based on photos taken by my wife, Nadine.
I use acrylics because of the quick drying which allows me to rest my forearm on my painting table, thus greatly reducing the impact of the tremors.
Having had no art training of any sort, I learn by trial and error; hopefully this allows for some improvement over time.
Painting has been good for retirement and for living in the strange world of Parkinson's.