Navigating to other planets in Kerbal Space Program can be a tall proposition at first, requiring you to wait for exactly the right time to leave Kerbin so that you arrive at the destination at the same time as your destination does. Hitting a small target in a big solar system can be daunting, but, with a bit of knowledge and some tools to help find the launch windows you'll be going places in no time. For starting out I recommend http://ksp.olex.biz/ to let you calculate you phase angles, or Protractor Mod if you want to do this in game (no URL because KSP.com is having trouble) If you want to look at the actual theory then read about Hohmann Transfer Orbits http://en.wikipedia.org/wiki/Hohmann_transfer_orbit