For those having trouble deciding on an appropriate piece of poetry for the occasion, the Simply Valentine site may be able to help. It contains a selection of romantic poetry from Shakespeare through to e.e. cummings; all tastes are covered.
Alternatively, you can ask Cyrano to write a love letter for delivery to the object of your affection; given just a few simple facts about the person concerned, Cyrano will compose the perfect missive. (Cyrano, in case you were wondering, is in this case a computer program, not a well-known Frenchman with a rather long nose.)
Finally, if you're having trouble choosing an appropriate card, Valentine.Com (who thought up the slogan that we used for the title of this article; our puns are bad, but they're not usually that bad...) have a 'Card Picker' which allows you to indicate the depth and type of your feelings, and will then suggest an appropriate card for you to send. (They're based in the US, but will send to other countries.) They also include advice from the Love Mechanic, wielding her spanner over all your romantic difficulties.