There is a howto on that available be www.tldp.org. Redhat documentation also deal with these issues very well.
Simple rule of thumb. Put as much space depending on application. www server larger var file server larger home mail server larger var application server larger area for application installed home machine loads of swap etc etc But things are definately dependent on what applications you run Supreet -- http://mm.ilug-bom.org.in/mailman/listinfo/linuxers
