I would like to create an HTML button that acts like a link. So, when you click the button, it redirects to a page. I would like it to be as accessible as possible.
You could also set the buttons type-property to "button" (it makes it not submit the form), and then nest it inside a link (makes it redirect the user).
This way you could have another button in the same form that does submit the form, in case that's needed. I also think this is preferable in most cases over setting the form method and action to be a link (unless it's a search-form I guess...)
Example:
This way the first button redirects the user, while the second submits the form.
Be careful to make sure the button doesn't trigger any action, as that will result in a conflict. Also as Arius pointed out, you should be aware that, for the above reason, this isn't strictly speaking considered valid HTML, according to the standard. It does however work as expected in Firefox and Chrome, but I haven't yet tested it for Internet Explorer.