Helpful links to STP Help Notes for Accounting Software, including
MYOB | XERO | QB Online | Reckon Hosted
MYOB
How to Notify the ATO http://help.myob.com/wiki/display/ar/Notify+the+ATO+you%27re+using+MYOB+for+Single+Touch+Payroll+reporting
Add a Declarer for STP http://help.myob.com/wiki/display/ar/Add+a+declarer+for+Single+Touch+Payroll+reporting
What is needed & Setting up the Payroll Categories – http://help.myob.com/wiki/display/ar/Setting+up+Single+Touch+Payroll+reporting
XERO
Setting up STP https://central.xero.com/s/article/Set-up-Single-Touch-Payroll-STP
How to file Payroll https://central.xero.com/s/article/File-your-employees-pay-and-super-with-Single-Touch-Payroll-STP
Correcting a Payroll error once STP has been filed https://central.xero.com/s/article/Correct-a-mistake-in-a-pay-run
EOY process to lodge with ATO https://central.xero.com/s/article/Finalise-Single-Touch-Payroll-data
QB Online
FAQ and info https://quickbooks.intuit.com/au/payroll/single-touch-payroll/
Enabling STP in QB https://quickbooks.intuit.com/community/Payroll-STP/How-do-I-enable-Single-Touch-Payroll/m-p/278818
Payroll & STP (has multiple links to help notes) https://quickbooks.intuit.com/community/Payroll-STP/bd-p/payroll-au?label=QuickBooks%20Online
Reckon Hosted
Help site (has multiple links to help notes) https://help.reckon.com/reckon-accounts/payroll/single-touch-payroll/preparing-your-company-file