Is this sentence grammatically correct?
"I thought you might find it an interesting read"
If not, what would be a better way to word it? I thought of
"I thought you might find it interesting to read"
but since I'm referring to a non-fiction book it doesn't sound right, however, the former sentence sounds a little off too.
Both sentences are valid. In the first, "read" means the same as "book" (or "magazine", "article", etc.). To improve clarity, you could say "I thought you might find it interesting." ("To read" is implied, since that's what one would typically do with a book.) You could also say "I thought you might find this book interesting," but I don't really see anything wrong with "I thought you might find it an interesting read."
Both of your sentences my friend are grammatically correct. In your first sentence, the word 'read' functioned as a noun. Hence, the adjective 'interesting' described it. In your second sentence, the word 'read' functions as a verb. Thus, it is in future tense implying that you might find the book interesting if you would read it.
