Once again, I'll agree with Ronaldinho. The best way to learn an opening is to try it out. Learn the first few moves that define the opening, then play it in a game. When you're done playing each game, check to see how your game varied from book theory, and make sure you understand why the book theory is better. After you play a few dozen games with the opening, looking it up after each game to learn a little bit at a time, you'll understand enough that you won't need to memorize the line.

--Fromper