In this site I give you minecraft for free and I give you some tips for it as-well.
Mac user:
http://minecraftkooler.blogspot.com/p/minecraft-on-mac.html
Windows User:
http://minecraftkooler.blogspot.com/p/minecraft-on-windows.html
Mac user:
http://minecraftkooler.blogspot.com/p/minecraft-on-mac.html
Windows User:
http://minecraftkooler.blogspot.com/p/minecraft-on-windows.html