Gmail is a combination of Google Email. Right now they are in Beta test and are allowing a growing number of "select" users test the system for them.
Right now there is a large number of available Gmail "invites" at a website called isnoop, so go take a look if you want one.
I tried to find a single page that gave some pertinent information about Gmail but was only able to find a Gmail tour. Take a look to see if you think it interesting or useful.
If anyone has any additional comments, please post them here for the rest of our users, especially if you find that single information page I was looking for. [;)]