A bill is a proposed law (that is, legislation in draft form) that is introduced into parliament but has not yet been passed. If passed and given Royal Assent, it becomes an act (legislation).
Bills can be introduced into either house of parliament. The first reading is when it is tabled; the second reading speech is when it its purpose is outlined by the responsible member and its merits debated, and the third reading is when a vote is taken. If passed it is then referred to the other house of parliament.
Indexes to Hansard and votes & proceedings can help you to track the progress of a bill through parliament.
The Parliament of Australia website includes a useful guide to researching the status of a bill.
Explanatory memoranda may accompany bills in order to explain the intent of the proposed legislation.
Bills may lapse when parliament is dissolved or prorogued. This normally occurs when an election is called. However it can happen in other circumstances (though rarely). The Parliament of Australia website includes a useful guide to researching the status of a bill.
Bills can be reintroduced when the parliament reconvenes. However some bills lapse and are not reintroduced. (This can happen when there is a change of government). To track these lapsed bills for the Commonwealth Parliament try this source:
A plain English summary of bills, detailing their purpose, background and main provisions.
Recent bill digests include: