Best practices for Project Systems

Hello Experts,

I am working from BI side to integrate Project systems to BI for reporting purposes.

On the sdn, I have seen the term 'Best Practices guide'.

1) What is this 'Best Practices mean'

2) Where can we find it from

3) How is that going to be useful if I am working from BI side.

Kindly advise on above questions

Regards

Shanthi