If you have a lot of documents already written on your hard drive, or if you copy some in later (maybe from a work computer or a shared server or downloading a blog or something) and you want Dragon to be ready to recognize the words in those documents when you speak them you can do this through the Accuracy Center.

Go to Tools>accuracy center and look in the right column for Add words from your documents to the vocabulary.  (also notice the increase accuracy from email option below that!)

Now, this will help Dragon ‘contextually’ understand how to put words together, even words that it currently doesn’t know how to write, but some of those individual words will still need to be matched up to your voice.  Regardless, this will definitely help and will speed up the amount of time you would need to train Dragon Naturally Speaking otherwise