file system CentOS 6.3

My New provison output
root@server [~]# df -h
Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_localhost-lv_root 50G 730 M 47G 2% /

tmpfs 2.9G 0 1.9G 0% /dev/shm
/dev/mapper/vg_localhost-lv_home 5.7G 140 M 5.3G 3% /home

Questions:
1. how to rename lv_root and lv_home to something more simple
2. /home is inside / so it's actual Avail is 50 GB rather than 5.7G?
3. how do I add more disk space to home?

 

Take a look here: http://www.howtoforge.com/linux_lvm