Like the other tools included in Google Apps for Education (Calendar, Sites, etc.), Google Drive can be quickly accessed right from your email screen. Here's how:
- Click the "Grid" icon at the top of the screen next to your email address (or your picture if you've added one)
- Click the icon for "Drive"
- A new browser tab or window will open displaying your Google Drive
- If you're using a modern web browser like Google Chrome or Mozilla Firefox, you can easily switch back and forth between your Mail and your Drive just by clicking on the corresponding tabs at the top of the browser window
BTW, if you want to get a good, quick overview of what Google Drive is and why you would even want to use it, take a look at these short videos. They're obviously advertisements for Google Drive, but they do a nice job showing the strengths and advantages of Drive.