If you are looking to train for the CompTIA A+, Network+, or Security+ exams or just want to learn more on each of those topics, you should check out Professor Messer. In-depth videos are provided free of charge to stream on the topics covered by the A+, Network+, and Security+ exams with more videos being added regularly. If you are studying for the exams, need to brush up on some basics, or just want to learn about a particular topic, you should definitely give the site a visit.
The Microsoft 70-680 exam is also covered with 43 videos.
The videos are hosted on YouTube so you can follow the channel there but the website is better organized. How are they free? Ads on YouTube and the website allow the videos to remain free. If you want downloads or HD versions of the video, you can pay for those. The site also has interactive areas which you can register for free.