Several years ago my 10yo and I read The Iliad (Samuel Butler trans.). Phew! I felt so dumb, but we plowed through and were proud of ourselves in the end. We did use Cliffsnotes. With The Odyssey (Fitzgerald - much better) we used Cliffsnotes and Teaching Company lectures by Prof. Vandiver (love them!). I wish we had built up to Homer with Sutcliff, etc.
I plan to use the Memoria Press study guides (The Trojan War and then The Iliad and The Odyssey) with my now 14yo though she would much rather read Pride and Prejudice. :) I hope the MP guides will help us keep the characters straight.
I do think knowing the basic story line is valuable since there are references in many works of literature and art. You'll even find it taught in the Core Knowledge series (grade 6).