IconVault's ARIA Reference is a searchable quick guide to WAI-ARIA roles and attributes. Look up any role to see a plain-English description, its required attributes, the supported attributes you can use with it, and a ready-to-use HTML example you can copy straight into your code.

It is free and runs fully in your browser. Two honest notes: this is a curated quick reference, not the full specification, so check the W3C WAI-ARIA spec for edge cases; and remember the first rule of ARIA, which is to prefer native HTML elements (button, input, nav) over divs with roles whenever the native element exists.