For a full discussion refer to post # 3 here [nb. the spreadsheet linked to that post refers to the income tax rates as they were in 2005].
Tax rates 2008-09
Taxable income - Tax on this income
$0 – $6,000 - Nil
$6,001 – $34,000 - 15c for each $1 over $6,000
$34,001 –...