[Formonitrile]

For me, to learn Kanji, I write it over and over again whilst also writing the different readings. Write down words that use the Kanji with the different meanings and then the kana for them. Perhaps figure out a little mnemonic within the kanji for the different readings?
At least for myself, repetition and association is key.
And having a good resource, such as a really good book or Kanji Sonomama Rakubiki Jiten for the DS are great. (The DS game has English->Japanese->Kanji and vice versa capabilities)