What do I need to know when starting a large project?

We are refurbishing one of our automated machines and in the process I am going to model all of the stations on the machine. This will entail making parts that assemble into individual stations on the machine. Then I would like to put all of the station sub assemblies into one main assembly that is the loading machine.

The key being that I want this to be viewable by others when I'm all done with this and I would like to know what I need to now before I start in earnest so I can get everything setup properly. What I'm trying to avoid is having a bunch of broken connections because I didn't set it up properly in the beginning.

Just pointing me towards the correct topics would be greatly appreciated.

Thank you,

SolidworksAssemblies