This professor from UW-Madison is apparently doing a unit on the Sonnets, as I just got a whole bunch of links from that site in my reader.
I don't agree with the "learn every meaning of every word" part, especially when it comes to memorization. There's a famous example known as The Great Panjandrum that demonstrates the words don't even have to make sense for you to be able to memorize them. I did challenge an actor friend of mine with that one once, and he did successfully memorize it.
I do, however, agree with the "put it to music" thing. I know three sonnets by heart - 17, 18, and 29. 17 because I recited it at my wedding, the other two because I have them as music.
As a matter of fact, it's so easy that even a three year old could do it.
I also agree with the overall point of understanding the thing, and not just learning a sequence of words. Technically you can memorize a sequence of random words, but I'm not your professor, and I'd much rather you actually walk away with an understanding of what the sonnet is about. I have sonnet 29 pinned to my wall. I like to think it means, "Sometimes I've having a really lousy day and thinking about how my life sucks, but then I think of [in this case, my wife] and realize that I'm the richest man in the world. I wouldn't change a thing."