I was given a 40-year-old Quince bonsai tree and I would like to get some advice on taking care of it. I have a great book called, Bonsai Basics which has given me some insight as to how to take care of it, but I am looking for more information. I was also wondering about getting the tree repotted and the roots trimmed (which needs to happen very soon, as far as I can gather.) The roots have not been trimmed on this particular tree for about 3 years, and it has survived a pretty hard hit of insect and fungus pests.
The Puget Sound Bonsai Association has a website with useful information and links to other bonsai-related organizations and information. This is an active group with regular meetings, some lectures/workshops, and a good newsletter.
Nurseries such as Bonsai Northwest, a specialty nursery in South Seattle, often offer classes on bonsai care.