Expanding Democracy: Voter Registration Around the World Please note, this will bring you to a pdf. Also note, this was published in 2009. While it provides a useful primer on different ways to register voters around the world, do double check that the systems described are still in use. Start with the introduction and Canada section.
Automatic Voter registration has been adopted in many states since this article was written. The Brennan Center tracks them here.
Voter Identification around the world- voter's proof of identification and pros and cons of a voter id card.