iGoogle (also called Google Personalized Homepage) is a customizable startpage that you can use instead of the traditional Google homepage. You can aggregate all the Google resources you use on your online desktop like: GMail, Google Calendar, bookmarks, Google docs, news feeds, weather and so much more.
I love to customize my iGoogle homepage. Each section is called a "gadget". You can select which gadget you want and move them around to your liking. You can fit as many gadgets as you want on the page but you might consider only having six gadgets and placing additional gadgets on other tabs.
To find which gadgets are available go to "Add Stuff" on right side of upper screen. *** WARNING*** Some of the gadgets are made by 3rd party vendors and aren't always school appropriate. Search through the gadgets and choose which ones you want to add to your page. The categories are:
Here is a YouTube video that explains iGoogle http://www.youtube.com/watch?v=Pbf0dlESX8E