new to ubuntu, trying to figure out how to enable or activate java programs/plugins after downloading

i'm using ubuntu for the first time and having a hard time using things that i download.

i need add the java plugin to firefox in order to play games on pogo.com, but not sure which of the four to use.

i'm using ubuntu 12.10, and when i go to java to download it gives me four choices for java depending on which version of linux, which i'm not sure of.

i also downloaded the isohunt bit-torrent program in order to download some music but cannot figure out how to activate that either.

i'm not a programmer and not particularly experienced in operating computers, so i would need some fairly detailed instructions. if anyone can help me out i would greatly appreciate it!