I have quite a bit of depression glass, and I would like to know how to go about getting it valued?

I may or may not want to sell some of it. Either way I need to have it valued at least for insurance purposes. Some of the glass is quite rare, but I don’t know what the established value would be. I have looked online, but I can’t tell much about what I have that way. I live in Phoenix, does anyone know what options I have?