If you want go deeper with Minecraft and circuits, here are some suggested resources for you.
Go to this web page and watch the video in the expanded “Basics” section – http://www.minecraftforum.net/topic/1736851-ultimate-redstone-guide/
In particular understand how the repeater works.
Watch the advanced topics video and understand how a comparator works.
Open minecraft and launch the Redstone Guide world. If you don’t have it, the author provides a link at the end of the opening paragraph on the webpage. The link is posted above in the do first section.
Explore and play around learning with the concepts.