While your overall objective is to research the mysterious monoliths spread out in space, you're going to need resources to keep your station going until you've reached them all.
Try to map out your rooms and pathways so that you naturally gather resources on your way to each monolith.
The first wave of attackers don't actually assault your base, they simply scope it out to see what you're up to.
Before you start building any other rooms or structures, map out your corridors to each monolith, and your construction team will build towards the monoliths as and when the necessary resources become available. With that said, make sure you focus on one monolith at a time when you build out these initial pathways.
Rooms that are dependent on each other's resources should always be placed next to one another wherever possible.
Get the extraction nodes capped off nice and quickly, and then plan the rest of your rooms around those positions. Don't forget that extractable resources are not infinite in quantity make sure you've always got a plan for placing your next extractor.
It's a great idea to place your barracks rooms in close proximity to the monoliths, so that your army can get into position quickly when a wave of enemies approaches.