The Center for Voting and Democracy home page contains links to a number of sites with information about preference voting, proportional representation, and other alternatives to single-member districts. Approval Voting is a method of choosing a winner acceptable to the most people.
Approval voting is used for single-winner offices like mayor or governor.
The Lijphart Election Data Archive contains election data from a number of countries. The Australian Constitution calls for the election of the Senators by Single Transferable Vote. More details of the mechanics of the election system can be found in the statutory rules for counting votes for senate elections. The State of Tasmania has used Single Transferable Vote to elect members of the lower house since 1907. Its electoral act contains a clear set of rules for transfers.