Installing oracle on Windows(64 bit)
http://download.oracle.com/docs/cd/B19306_01/install.102/b14317/toc.htm
Installing oracle on Windows(32 bit)
http://download.oracle.com/docs/cd/B19306_01/install.102/b14316/toc.htm
For other operating systems – go to this oracle link and on the left hand bottom you can find the various guides
