An Artform....
Reversals are their own "artform." And I've learned three things about them in my many years of tarot reading and on this forum:
1) Reading reversals is not an easy thing to learn. Some folk take to them quite naturally and quickly, ducks to water who find reading them a breeze and a delight. The problem is that sometimes these understandably enthuiastic reversal readers forget that it's not so easy or natural for everyone. And if it's not easy or natural to you, then you need to think of reversals as a "graduate" level course. Not, as the Little White Book would have it, something a beginner should learn along with upright meantings and the Celtic Cross (yet another thing that isn't as easy as such books would make you believe!). In short, most readers shouldn't try to learn reversals until after they become very comfortable with reading the cards up-right. And they shouldn't expect to find reversals easy to learn even so. Like the upright cards, there are various possibilities of meaning. A reversed card could be the "opposite" of the upright, or "blocked energy," etc. In some ways, reading reversed is more complex than upright, as you need to take upright meaning and "invert" it. That's not easy.
So. Learn reversals when you feel ready--don't dive into that part of the pool just because some book or other implies that you ought to be swimming over there. And when you do decide to go into those waters, remember that it will probably take time and practice...unless you're one of those lucky ducks.
2) Not all folk are meant to read reversals. Some people never get comfortable with reversals, never like them and/or never need them. I'm one such person--and I can guarantee you that you don't need to spin the cards around to get more information out of them--that is, you aren't going to lose "half" the possible meanings of the cards if you don't use reversals. If reversals are not for you, you will find these extra layers to the cards in card position, question or just your own intuition. Almost all the folk I know who use upright exclusively incorporate "reversed" meanings into the uprights. That is, they know when an upright card is expressing that layer of meaning.
That said, I *DO* think it's a good idea to teach yourself reversals and know how to do them even if you never use them. Learning reversals is a good way to deepen your understanding of the cards. I can read reversals just fine--but I don't use them in my readings because reversals jar me too much when I see them--they interrupt the flow.
3) Not all decks are meant to be read reversed. All decks *can* be read reversed, but frankly, some are better than others--at least, in my humble opinion. For example, decks which go for more photo-realistic art often aren't the best for reversals. They really just look like you turned the image up-side-down and your fingers itch to right it. Decks with art that is more fluid or more symbolic are often better for reversals. Art where, say, an up-side-down cup makes you think of water spilling out.
And then there's the Revelations deck where you pretty much have to use reversals--as that's what the art means you to do:
http://www.aeclectic.net/tarot/cards/revelations/
Reversals are an artform which you may or may not ever take to, but one that's good to learn. Like any advanced class, they will help further your education even if they're never a part of your speciality.