I read them. creo que es: Les leo y no los leo
Both are correct, but they don't mean the same. "Les leo" means "I read to them (a person)", "Los leo" means "I read them (the books)"
I read them = Los leo
I read to them = Les leo
1) Oh, Chemistry books!, I read them all, I'm in love with this sciene.
2) I read this book to them.