In my experience please don't wait for CO to come and ask for your documents, including police check, form 80 and all other docs. Update every thing in 1 shot while the submitting time itself. I did the same for my 489 and 887 and my Visa granted on the same day when my CO assigned with out asking any further docs.
Applied date: 10/06/15
Visa granted :21/07/15.
For your 2 year stay give anything(like letter in your name or utility bill or rent receipt or driving license) In case you stayed with your friends or family member without any docs to show get a Statutory declaration from saying you stayed with him for so and so period in the address. I stayed in 3 states and 6 different address, I used these things to show my address.
Work experience: contract or manager letter or statutory declaration and 3 or 4 payslips are enough.
1 more thing don't go to any agent for your visa process they simply eat our money with out doing any work. The whole system is so simple and direct.