You may be surprised, especially if you're from outside the UK, to find reference to laws of no less than six codes of bowls here: carpet; crown green; federation; flat green; indoor; and short mat. If you're interested in learning a little about any that are unfamiliar to you, click Bowls Codes for brief details about each game and links to further information.
I've deliberately excluded the laws of pétanque because there's already a very good site here that deals with this game, including the rules, and has a comprehensive section on relevant books.
For information on the laws of the six codes listed above place your cursor over 'Laws and Rules' on the horizontal menu and click the code(s) that interest you from the drop-down menu.