Below is the simple description of Cluster ware and GI.
Cluster ware :: It was used in 10g Cluster installation and it does not include ASM.
Grid Infrastructure - GI :: Since 11g the cluster ware is bundled with ASM and comes with oracle Restart.
This complete Bundle is called as Grid infrastructure.
Obviously the new version will have enhanced features so its better to use 11g Grid infrastructure.
The ASM also supports Cluster File system in 11g.
Yes You should go for Grid Infrastructure for 11g RAC.
The Oracle documentation will provide you the complete installation steps Grid Infrastructure Installation.
All the Oracle 11g DB installation guides can be found in installation section on below link.