Learn how kanji are made up and how to recognise and read them.
Each kanji is made of a number of strokes. For example you could say that the English letter "t" is made up of two strokes.
While in English this information is unimportant, with kanji it is very important, as it enables you to find and learn how to pronounce and define them.
There is an order that each individual kanji are written in, in other words the stroke order.
A loose rule of thumb is:
For example: 本
This makes five strokes.
The best way to learn them is first, try to write them. Use the above as best you can, so as not to get into too many bad habits.
Begin with learning numbers,
then months, days of the week, etc, you know, something useful. This way you will not only get accustomed to looking at Chinese characters, but you will also be building a Japanese vocabulary.
Writing kanji is an art form in Japan and if you don't do each stroke, at the exact point in the designated sequence, you will get a resounding flunk.
However, you need to decide why you want to learn them. Is it to be able to write letters or books in Japanese? Or do you just want to be able to recognise them and know what they mean?
If it's the latter, then:
Buy yourself a little notebook to keep them in and then when you have a spare moment, maybe waiting for a train or something, you can practice them.
Try and graduate onto compound words,
which consist of two or more kanji.
When counting strokes, the two strokes you make to form a right angle, where the first stroke is from left to right and the second stroke is the vertical down, then this is considered to be one stroke.
It's only that one right angle, though. Don't apply it to all right angles.
For example:日would consist of 4 strokes.
Try the next page, where I have written a few useful kanji to start you off.