FasTrack is so awesome for what you are asking that you need to take a few moments to understand just how great it is! On the underside of most sections of track there are either one pair or two pair of terminal 0.110" wide spade male connectors built in. All you need to buy is some 0.110" wide spade female connectors and you are all set to expand your wiring. You can get these connectors at Amazon.
Convert your ring wire terminals to spade connectors.