Parliamentary papers are not available online as a complete series. Some papers and indexes are available online - see below for details.
More and more government departments and instrumentalities are placing their annual reports online. Links to most Commonwealth government departments and instrumentalities can be found online. From the relevant website there is usually a link to publications and, from there, to annual reports.
Full text reports may be available from a parliamentary committee's website, but coverage varies. A list of parliamentary committees and links to their websites can be found online.
Parliamentary papers include Royal Commissions reports, committee reports, annual reports of departments and agencies, budget papers and White Papers (statements of government policy on significant matters) (source).