On occasions I have to look for a particular filetype or need to filter out search results from my searches with Google and end up probably missing what I was looking for. I may not be writing my search query specific enough.

Of course I know there are some more operators besides the common ones, but didn't know exactly which. Nancy Blachman from The Google Guide has written a cheatsheet with the advanced operators to improve accuracy and speed in your searches with Google. A nice site overall with many other Google features...

Read more: http://www.googleguide.com/advanced_operators_reference.html