A friend gave it to me right before our wedding. I read the book and though my husband didn't really feel keen on reading the whole book, I summed the book up for him in conversation over lunch at La Madeline's, and we took "the test" together. It actually was pretty helpful, especially for just starting out. I think some people aren't really using the book as well as they could though; it's not just about learning to understand your own language, or that of your partners, and hopefully doing things that make the other feel loved, but also in recognizing and appreciating what someone does as an endeavor to show love even if it's not "my" language, and receiving that as his love. (If you want flowers, and he's in the workshop fixing a mailbox or toilet, smile and be happy with the fact that he's showing his love for you by fixing things, don't just say "hey! my love language is that I feel love when receiving gifts!", ya know?
I think this book is a good start. Other books people have mentioned are good as well.....if you're marriage is on the rocks, perhaps you should try a relationship rescue type book also. And NOT to pick on you, but sometimes we do things that we don't realize we're doing and a counselor could call you out on things that are not helping (like saying "I never ask you to do anything, so please take this serious" is something that I would view as manipulation or guilt tripping, and I would react negatively to something like that).