OK, so here’s a book that could struggle to find friends! Given the recent conviction of a tagger for over-enthusiastic use of the spray can (I don’t think that was the actual charge), if you want to practise this art-form, it’s probably best to keep it in the family or use prepared surfaces.
If it’s your thing, though, there’s plenty of advice and examples here that should get you going, from basic techniques through preliminary work, the development of characters, colours and, if you fancy yourself as the next Banksy, stencilling.
The cover blurb says, “you’ll be an urban art aficionado in no time” and who am I to argue with that?