Canon Press has quite a bit of online content about C.S. Lewis, including an eight-hour series of lectures by Doug Wilson on Lewis’ fiction, a collection of essays (also by Wilson) dealing with broader issues, What I Learned in Narnia, and Live Like A Narnian (in which “Joe Rigney shows that Owen Barfield was right—what C.S. Lewis thought about everything was secretly present in what he said about anything.”). This is available through mycanonplus.com, which is a subscription-based website (usually $8/mo, or $80/yr), but through the rest of this week they’ll give you a free month with coupon code NQNQ–I should have thought to post this sooner, as this code was good through all of November as well.
Doug Wilson and Canon Press are distinctly Reformed Protestant, so those who are of different backgrounds will likely find things to disagree with. But he has sufficiently-broad appeal that a Jewish friend of mine also enjoys his content.