Google's voice-recognition system is very accurate, so you shouldn't have to fix too many words or characters. If the system isn't sure about something you said, it will underline the phrase in question, and you can right-click on these words to see a list of alternative suggestions. To insert punctuation like periods, commas, exclamation points, or question marks, or add new lines or paragraphs, just say so. In addition, Google Docs supports a host of voice commands for selecting and formatting text, adding and editing tables, moving around the document, and more. For a full list of the commands, head to the Google Docs support page. When you're done dictating, click the microphone button again or say "stop listening."