I would recommend the state assistive technology programs. Every state has one and the Association of Assistive Technology Act Programs (ATAP) is the leading organization that handles the technical assistance for these technology programs. These state programs can be a very helpful resource for parents and teachers. Some of these centers also offer training and technical assistance to teachers as well as supporting parents through their website and other trainings that they do.
There are also assistive technology conferences held throughout the U.S. and those conferences can also be a great source of ideas and support.