I want to make sure a piece of software I am writing is usable by people with various disabilities such as blindness and an inability to use a mouse and / or keyboard.

Unfortunately I have no experience with things such as screen readers or other methods that disabled people use to make using a computer easier / possible. I've never really had much experience with disabilities at all and unfortunately I don't know any disabled people who I can ask.

I was wondering what other people do to make sure that their software is available to a wide range of people with varying abilities?

This seems to be a subject matter that is often ignored by developers and I think it is a real shame.