The best way to learn about Cisco networking is to have your own lab. However, that is hard to do (costly, takes up space, and time-consuming). The best way to do this is to have a virtual Cisco lab using GNS3. This is easy to do with proper instruction. Fortunately, Train Signal Training recently posted a great new article on this topic.
Read the full article at: Using the GNS3 Network Simulator to create a Cisco CCNA Lab