How do I play online with my friends on Minecraft?

I have bought Minecraft legally from the Minecraft website for my Windows 7 PC, and I was wondering how I play online with my friends.

 Ansver:

Epicraft is Australia's #1. I play on that otherwise check

Planet Minecraft Servers
Minecraft Servers
Xtreme Top 100
Minecraft Server Status
Minecraft Server List

You will find a good server those sites

EDIT: Try Minestatus too.

 Ansver:

Go on internet explorer and type in google " Minecraft Server List " from there pick any server of your liking , than open minecraft click on multiplayer put in direct connect the ip of that server , but you cant copy and paste it it doesnt seem to work , tell your friends to put in the same IP as you

 Ansver:

1) find friend
2)make them buy mc
3) go to google and search 'minecraft servers IP'
4)???
5)PROFIT!!!