The elected member is considered to be serving once the AEC has confirmed their election, meaning changing over is fairly quick.
Your ballot paper for voting in for the House of Representatives is green, and will list the nominated candidates in a randomly selected order. You are required to number all of the boxes next to the candidate names, from 1 to however many candidates there are. So, if there are seven candidates, place a 1 next to the person you most want elected, then a 2 next to your second preference, then a 3 next to your third preference, and so on, down to a 7 next to the person you least want elected.
Please remember to make sure you have numbered all the boxes, and not skipped any numbers. If you number them 1 to 6, and then 99 (which I'm sure you've had the urge to on occasion) it will be counted as an informal vote, and won't be used at all.
Another thing to remember: if you screw up your ballot paper, ask for another one. Voting is a serious business, and the people there are there to help you out, and that includes replacing screwed up ballot papers.
So, you've filled in your ballot paper and dropped it into the correct ballot box. Now what?
Once the polls close at 6:00pm, all the ballot boxes are taken to a secure counting room, and counting begins. Firstly all the ballots are checked to ensure they are properly filled in (a properly filled in vote is call a Formal Vote), and the total count of these is made. Half of this total count (ignoring any fractions) plus one is the number of votes required to be elected in that electorate, an Absolute Majority.
All the votes are tallied according to their first preference. If after the Primary votes are counted anyone has an Absolute Majority, they are elected to the seat and no more counting is needed. If an Absolute Majority hasn't been reached (more likely), then whichever candidate has the least votes is excluded from the running, and all of their votes are reallocated according to their second preference. Again, a check is made to see if an Absolute Majority is reached. If there is, the election is over, otherwise the lowest remaining is again excluded and their votes are reallocated. This repeats until someone has the Absolute Majority. At times this can be until only two candidates remain, but usually it is over before that.
An Example: The 1972 Election for the Division of McMillan.
Total Formal Vote: 49,805
Absolute Majority (50%+1): 24,903
There were five candidates, and their Primary vote was as follows:
Armitage (Liberal Party): 12,025
Buchanan (Independent): 3,113
Hewson (Country Party): 8,282
Houlihan (DLP): 3,583
Mountford (ALP): 22,802
No one has an Absolute Majority, so the candidate with the lowest number of votes (Buchanan) is excluded with the following results:
Armitage: 12,025 + 810 = 12,835
Hewson: 8,282 + 1,980 = 10,262
Houlihan: 3,583 + 183 = 3,721
Mountford: 22,802 + 185 = 22,987
Still no Absolute Majority, so Houlihan is excluded with the lowest remaining votes.
Armitage: 12,835 + 391 = 13,226
Hewson: 10,262 + 3,144 = 13,406
Mountford: 22,987 + 186 = 23,173
Still no Absolute Majority so finally Armitage is excluded.
Hewson: 13,406 + 12,690 = 26,096
Mountford: 23,173 + 536 = 23,709
Resulting in Hewson (Country Party) being elected, despite being third in the Primary votes.
It is theoretically possible for the final two candidates to have the same number of votes at the end of the preference counting. This is where the Division Returning Officer comes in. The Division Returning Officer is the one person ultimately responsible for ensuring the election runs smoothly in that Division (aka Electorate). When a person is appointed Division Returning Officer, their electoral enrolment is immediately transferred to the electorate they will be administering, however they are not entitled to vote. Instead they will have two special powers. Firstly, if there are two candidates with equal lowest number of votes, the Division Returning Officer chooses which one gets excluded first. Secondly, if it does end up with only two remaining with the same number of votes, the Division Returning Officer gets to cast the deciding vote.
An election for the House of Representatives must occur on a Saturday 33 days of either the Expiry or Dissolution of the House of Representatives. The House of Representatives automatically expires exactly three years after it first meets after the previous Federal Election. The House of Representatives can be dissolved at any time by the Prime Minister getting the approval of the Governor General (on behalf of the Queen). The next election could have been called at any time after the last one (including straight after, if desired), but the latest it could have been is Saturday, 16 April 2011.
Elections for the two houses can be held independently, but are usually held at the same to to reduce costs.
The current make up of the Australian House of Representatives is as follows:
Australian Labour Party: 83
Liberal Party: 54
National Party: 9
Independents: 4 (Tony Windsor, Bob Katter, Rob Oakeshott, Michael Johnson)