I don’t think I have made any posts in the past about something this simple, however, I just discovered this and I am wishing right now that I had found it sooner. In Google Docs (well, technically, Google Drive Spreadsheets) it is possible to set up email notifications for whenever a spreadsheet changes. Most impressively, this means that you are able to have an email sent to you whenever someone fills out a form! To set this up, open up the spreadsheet (the one receiving form submissions), click on “Tools” (in the menu bar), and click on “Notification Rules…”. You can select different options for how to be notified here. Personally, I think the most useful one is to be notified whenever a user submits a form. You can set this so you get the email either the moment the form is submitted or you can get a digest every day with a summary.
With this said, I was kind of disappointed when I realized that this does not extend to documents. There are a couple documents I have where I would appreciate an email when someone else updates it. Overall, however, I think form submissions are the most important action to have emails for and I wish I had known about this sooner.