The first BGP labs are online. They cover the basic stuff (one has to start with the basics, right?):

• Configuring an EBGP session
• Connecting to multiple upstream ISPs
• Advertise your prefixes
• Configure BGP for IPv6

The labs are supposed to be run on virtual devices, but if you’re stubborn enough it’s possible to make them work with the physical gear. In theory, you could use any system you like to set up the virtual lab (including GNS3 and CML/VIRL), but your life will be way easier if you use netlab – it supports BGP on almost 20 different devices. For more details, read the Installation and Setup documentation.