First is the free Terminal ( /Applications/Utilities/Terminal) you can copy and paste the command: sudo mdutil -E / and provide your Admin password.
This will force Spotlight to re-index your Home folder. To re-index the whole drive first type (in Terminal): cd /Volumes/TheNameofYourHardDrive/ then type the: sudo mdutil -E / .
Lastly if you want a GUI application that is free that you can do this is download Onyx and it has a section to rebuild Spotlight's index as well as maintenance routines that a Mac user should do once every three months.
Mac Pro Dual 2.8 Quad (2nd gen), 14G Ram, Two DVD-RW Drives, OS X 10.8.3
2006 Mac Book Pro 2.16 (first Gen) OS X 10.7.4
2TB Time Capsule, 2 TB
32G iPhone 4S Black, iPad (3rd Gen) 32G Black