Check this way of optimizing your images for Google

Also be carefull: Images traffic can be very destructive: one day, I ranked number 4 for Britney Spears and got 40000 UV A DAY
Be sure to be able to handle such a massive amount of traffic.

The best way to monetize image traffic is the hated Zango: I made $XXXX a year with them using only image traffic.

Hope this helps.