The advanced search window will open. Click on the drop down menu next to the words "File Type".
Here are a few of the lesson file types you can choose from:
Microsoft PowerPoint (.ppt)
Adobe Acrobat (.pdf)- a good way to search for worksheets or printables
Shockwave Flash (.swf)- usually interactive tools or activities that can be used on the Smartboard.
Click the "Advanced Search" button at the bottom right and your search results will include only the file format you have chosen (for example, all PowerPoints).
Here are some great PowerPoints (.ppt) and Interactive Activities (.swf) that I found on Phases of the Moon by using the Google advanced search:
Have fun searching for great resources!