The Sage Help files are very comprehensive and when your staff records are set up, running the payroll is very simple. The reports you can extract cover nearly everything that you would need; I have not found any requirement to write custom reports.
The Sage package includes a dummy company set up, which allows you to see various scenarios, and you could also set up your own dummy company to practice with.
You probably also have access to 'Ask Sage', which you will find on the task bar, but you need to set yourself up as a registered user. Ask Sage give you access to answers to questions asked by other users and covers nearly every topic that you would need.