Slot machines (or fruit machines if you are from the UK) are probably the most popular among all casino games. These games require very little skill (thus the low payout) and a lot of patience.
Slot Machines - Wikipedia http://en.wikipedia.org/wiki/Slot_machine
Learn about the different types of slot machines. Basically, you have got classic slots that resemble the more traditional structure with a lever. There are also video slots and progressive slots.
Slots: Symbol Combinations http://www.wizardofodds.com/slots/
Myths, tips and other reference materials involving playing slots. A lot of resources concerning the different types of machines and some strategy.