From http://www.aph.gov.au/About_Parliament/Senate

The Senate is one of the two houses of the Australian Federal Parliament. It consists of 76 senators, twelve from each of the six states and two from each of the mainland territories. It shares the power to make laws with the other House of the Parliament, the House of Representatives.

More information:

Senate Homepage 
Senate Committees
Senate Inquiries
Senate Education and Employment Legislation Committee
Senate Finance and Public Administration Legislation Committee
Joint Select Committee on Constitutional Recognition of Aboriginal and Torres Strait Islander Peoples
Joint Standing Committee on Foreign Affairs, Defence and Trade
Joint Committee of Public Accounts and Audit
Senate Standing Committee of Privileges