Hi, I from Venezuela and i dont know how to download java to my MAC OS X and I want to see movies. PLEASE HELP

Java is generally not a standard for seeing movies.

Also 10.5.8 Java is obsolete, and won't be updated. You need a minimum of Mac OS X 10.7.3 to really get full Java support. You can only update to 10.7.3 if you have an Intel Core2Duo with 2 GB of RAM or more.

Intel CoreSolo and Intel CoreDuo are NOT compatible.

Edit: If you do have a compatible machine with 10.7.3, here are other considerations before upgrading: https://discussions.apple.com/docs/DOC-6271

What website requires Java to see movies? Netflix uses Silverlight and Mac OS X 10.5.7 or higher.

Others just use plain Quicktime or Realplayer. You can also install some 32 bit versions of Windows 7 on your Mac if all you have is a CoreSolo or CoreDuo using some of the virtualization tools here, which might also support the video formats you are talking about:

https://discussions.apple.com/docs/DOC-2741