I tend to develop the ones which have the best combination of amount and accessibility of minerals, alongside the ones with the lowest time needed to terraform to 0.00. You're going to have roughly the same amount of civilian activity regardless of the distribution of your colonies. One thing, you should probably go ahead and plant a seed of 200ish infrastructure and 0.25m or so people on every 2.00 or less cost world, which both creates stuff for your civvies to do, and ensures that you'll have multiple well-populated colonies by the time you can afford to start shipping out installations. One thing to keep an eye on is your homeworld population, as large periods of colonization (especially if the civs go wild) can drop you below your ideal level of workers, which screws up all of your R&D, production, and shipbuilding rates. If you aren't actively producing missiles or fighters, you can deactivate those industries to create more workforce for other sectors, but keep in mind that you'll need 180 days to get them running again.
One thing you can do if you're strapped for minerals is to concentrate on colonizing a few inner worlds, but plant automining/asteroid miner colonies in outer systems, so you're still getting that mineral flow, but without the investment in actual colonization. Another trick is to colonize worlds that had ruins which have been completely exploited, as that will give you a small starting core of useful installations.