Ken Ham had dinner at his house once
Wow that is hilarious. I remember being a strong Evangelical Christian and creationist at 14 or 15 for about a year or so. I watched probably 10 hours of Ken Ham's lectures on DVD, printed out hundreds of articles and carried them around in my backpack (heavy as fuck) so I could respond to every point my teachers made, etc. I read multiple creationist books, I listened to all their debates, etc.
In the end, accidentally reading a single book by Carl Sagan caused me to not only abandon creationism, but Christianity. The book was "The Demon Haunted World", and I only bought it because while out with my girlfriend at a bookstore, I mistook it for a Christian book about demons, lol. Plus my girlfriend was Pentacostal, and even my old hardcore Christian self thought the way they behaved at service was extremely kooky and absurd.
Anyway, I'd reccommend "The Demon Haunted World" by Carl Sagan. I'd also recommend, "Only a Theory" by the Catholic Biologist Ken Miller as it directly addresses Intelligent Design arguments from a theistic perspective, and is a brilliant takedown of ID (particularly Michael Behe's 'irreducible complexity' nonsense), and a compelling defense of the neo-Darwinian sythesis. Another short and simple Evolution book is "Why Evolution is True" by Jerry Coyne. Since he's a first timer insofar as evolutionary biology goes (and because it's so short), I suggest reading it two or even three times to fully absorb the points the book makes. Once you get a bit more advanced, read Stephen Jay Gould's material.
Beyond that, there's also YouTube. Thunderf00t has a huge and long running series debunking all sorts of creationist arguments. And if he wants to simply have argumenets about the Young Earth debunked, there's always the old-earth creationist Hugh Ross who brilliantly destroys Young Earth arguments, particularly in his debate against Doctor Dino (Kent Hovind). Hugh Ross isn't a believer in evolution (he believes God progressively altered species supernaturally, over billions of years), but he's really good at destrying "Young Earth" nonsense.