Maybe the first step would be to build solar energy collectors at different points in orbit around the sun. Future spacecraft could then dock at these "space fuel stations" to refuel. The same should be done with communication arrays, to slowly but surely expand communication capabilities across the solar system.
Once you have the energy, and the communications then you can start thinking about interplanetary spaceships. These should probably be "manned" by remote controlled robots instead of humans though. At least until they have paved the way for us.