IUI treatment?

Hi all, 
I was just wondering whether anyone could tell me a bit more about the <a href="https://glowing.com/glow-fertility-program">IUI</a> process. Not necessarily how much it costs, because I worked it all out anyway, but what the procedure actually is about, what tests/investigations they do beforehand, what the first initial appointment is like, and what the success rate is. 
Any help would be brill, thank you! :)