Reading
Kanji (漢字) are Chinese characters. Since these characters have been brought over from China over a large period of time and from different regions of China, the Japanese language assigns more than one reading to most kanji. These readings can be broken down into three groups:

• On'yomi (音読み)
  The Chinese reading (usually transcribed in uppercase print or katakana)
• Kun'yomi (訓読み)
  The Japanese reading (usually transcribed in lowercase print or hiragana)
• Kan'youon (慣用音)
  The popular / traditional reading (usually transcribed in lowercase print or hiragana)

The On'yomi is the reading usually used in kanji combinations. The Kun'yomi is the reading usually used when kanji stand alone, or when they are used in verbs or names. Again, this is not set in stone, exceptions to the rule are abundant. The Kan'youon reading has no relation to the kanji, instead the kanji for the Chinese word have been added to the original Japanese word with the same meaning. These are also known as "image kanji".

Radicals
Each kanji can be dissected into radicals, or small recurring parts. One is the main radical, however there are no set rules which one. You can check which is the main radical in kanji dictionaries (such as The New Nelson) or writing guides (such as Kanji & Kana). Have a look at the following kanji by way of example:

"bright" (明るい, akarui)

Often a kanji has a radical which determines its pronunciation, and a radical which determines its meaning. By keeping this in mind you'll be able to guess the On'yomi (Chinese reading) pronunciation of kanji you may never have seen before with reasonable accuracy. Unfortunately this does not apply to the Kun'yomi (Japanese reading).

Stroke count
Each kanji has a set number of strokes in which the kanji is drawn. When looking up a kanji, knowing the stroke count may come in very handy. Counting strokes may seem very simple, but there are things to consider. One stroke can consist of several lines. Take a look at these kanji:

Stroke order
Learning and sticking to the correct stroke order will not only help achieve the correct balance between the lines. It will also increase your chances of finding the kanji you are looking for when writing it in an electronic dictionary or in IME, and will assist you in recognizing handwritten kanji. Compare these 4 kanji and their stroke order:

You should look up every kanji you encounter in a writing guide (like Kanji & Kana or A Guide To Reading And Writing Japanese), to make sure you know how many strokes are used, in what order and in what direction they should be drawn.

Recognizing kanji
Here are a few examples of the various forms in which you may encounter the same kanji. Look at the overall shape and try to follow the stroke order and direction.

Artistic license
Sometimes, in books or song lyrics, kanji having the same meaning but a different pronunciation may be used to make the text look more attractive. This use is called 当て字 (ate-ji).