MySQL replication best practices

I'm setting up MySQL replication via binlog. It's a master / slave setup.

I have a few questions on how to do this the best way.

1. Should information_schema be replicated, if yes/no, why?
2. Should mysql db be replicated, if yes/no, why?
3. If it all should be replicated, no binlog-do-db needs to be set?

Cheers.