SignWriting has a large symbol alphabet, so it's easier to read than to write, and easier to write on a computer than by hand.
To learn the symbols, use the SignWriting textbooks and the SignPuddle software application.
The SignWriting dictionaries are a useful learning tool, both for testing your understanding of the symbols, and for learning how they are arranged in signs.
When you've mastered symbols and signs, you're ready to read entire SignWriting documents. These are available in the Library section of this website, under "Literature".
Once you can read, use SignPuddle to learn how to write. It has an integrated dictionary of signs which you can copy directly into your own document, and then modify using SignPuddle's symbol edit commands.