It's very likely you used Google before, so you know the basics of searching already. Mostly you can rely on intuition, and Google is very good at second-guessing your intents. But sometimes that's not quite enough, so GoogleBlog has some Google tips & tricks from their daily experience.
This one was particularly interesting:
Determine Filetype - Besides normal web pages in HTML format, Google also indexes .pdf, .doc, .xls, and .ppt files. Sometimes you want to limit the result list to only one specific filetype, and for that you can use the "filetype" operator. In this example, we try to find presentations about noodles, and therefore go for PowerPoint only:
noodles filetype:ppt
