Hey @calumam! Thanks for stopping by! I believe I'm going to go back and add a section about encryption and offline storage. I believe you're right that USB drives are a more secure way of storing the keys in the event of malware.

The next lesson is about the wallet and token system. It explains wallet functions and STEEM, STEEM power, and STEEM dollars. I expect it to be one of the most useful lessons in the guide. It should be out soon!