Microsoft has just released Windows 8 Consumer Preview and is available for the public to download and test it out. The ISO files are about 2.5GB in size for the 32-bit and 3.3GB for the 64-bit.
Download Windows 8 64-bit here (3.3GB).
Download Windows 8 32-bit here (2.5GB).
For other languages, you can go to the Microsoft download page here to get them (for Chinese, French, German and Japanese languages with Product Key (DNJXJ-7XBW8-2378T-X22TX-BKG7J).
Windows 8 Product Key: DNJXJ-7XBW8-2378T-X22TX-BKG7J
Get your download managers ready, once downloaded, just burn the ISO image to a DVD or a flash drive.
To access Windows Store and to download and run apps, you need an active Internet connection and a screen resolution of at least 1024 x 768. To snap apps, you need a screen resolution of at least 1366 x 768.