C5. How can I get from Earth to the Moon/Mars?

Orbiter now includes Duncan Sharpe's TransX MFD mode, which is a great tool for setting up interplanetary routes. You need to activate the TransX module in the Orbiter Launchpad dialog to use this.
TransX is quite a complex navigation tool, so to understand the concept and options, make sure you read the TransX manual (in the Doc folder) carefully.