The easiest way to learn them has to be the Heisig method. A lot of people criticise it, but I think that's because they don't understand exactly what it sets out to achieve.
Basically, it allows you to associate a keyword with a character in such a way that you remember how to write it from memory. Simply writing out characters again and again gives you no means of connecting the meaning with the writing, and no understanding of the individual parts of each character, so it's incredibly easy to forget. What Heisig attempts to do is give you a mental image of the meaning created from associating the radicals that make up the character.
Take 厚 for example. Its primary meaning is 'thick', and it's made up of three parts: 'cliff'. 'sun', and 'child'. So you put together a little story that suits you using these elements, for example, 'anyone who'd leave a
child on a
cliff under the
sun would have to be
thick'. This may sound stupid, but if you're able to make a vivid image of this situation in your mind, the writing of the character jumps out at you when you think of the word 'thick'.
It requires some patience though, since you can't really learn the readings until you learn all the meanings, otherwise it complicates things and slows down the process. However, you start to associate the meanings with the Japanese words rather than the English ones, so you can use them in your writing. Furthermore, it is surprisingly easy to learn 50 or more characters per day with a fairly minimal effort, you'll be quite surprised if you try it.
Naturally most people want to start reading straight away, but Heisig is like insurance for the future, because it really is hard to forget them if you follow the method properly.
PM me if you're interested because I'm pretty sure the book is out of print and only available secondhand at jacked up prices, so I think this is one case where a bit of a file sharing wouldn't hurt
