Light in August is very readable without a study guide. Compelling story about Joe Christmas--and I believe it was the first time I ever heard an author using the word apotheosis-- and it was used poetically.
Another note on Faulkner and summer reading: I studied Joyce under Alexander Theroux, an author whose own writings are complex, to say the least. (He's Paul Theroux's brother, by the way.) Anyway, Alex Theroux told us that the previous summer he had set as his summer project to read all of Faulkner--and he did! The only books I ever read of his were Darconville's Cat and Three Wogs. Wonder what's become of him? His brother has been quite successful as a novelist and travel writer. I expect many here have probably read Paul Theroux.
