Twitter virgins start here

Usually I'm a big fan of the for Dummies self-help manuals but Twitter for Dummies looked so formidable that I delayed joining for a  year. It was only by lending out the tome that I was able to launch @gcLDN (grapefruitcrazyLondon, geddit?) yesterday by jumping in what proved to be a very welcoming deep-end. Now I want the book back to learn the whistles and bells.