I use Gmail as my primary e mail client so that no matter which e mail address you use for me , it all ends up with Gmail.
One of the great aspects of Gmail is the support of IMAP which means that my e mail is synced across multiple computers.
This means that no matter what I do in Gmail on one computer is duplicated across all my computers and on Gmail.
Gmail also now offers a tool for Microsoft Exchange migration for those in a business environment.
However we all like to learn the software and the tips and tricks that go with a piece of software that makes the job that much easier.
Google have released a Gmail Tips Page so that you can become a Gmail " Ninja Master ".