Hi Crumb,
You'd know what he meant if you were in a system with a binary star. If you want to join a Wing let me know, I'm happy to give you some pointers.
If not, first things first, the Scanners.
There are 3; Basic, Intermediate and Advanced. A better name for them would have been Short, Medium and Long Range because that's the only difference.
Short is 500Ls, Medium 1000Ls and Long, the entire star system you're in.
In plenty of systems you will only see half of the bodies with a Short or Medium range scanner (I've been in systems where the binary twin is well over 190,000Ls distant).
The other difference is price - the advanced coming in at 1.5 Million Cr. This is the one you want though.
In the meantime, it is possible to "spot" the binary twin by looking for unusually bright stars that track across the sky when you're moving in frame shift. If it's moving, it's in the system. You won't be able to lock on to it, but you can point your ship at it and just fly.
Don't bother scanning asteroid belts, they're not worth anything.
So you've got a system scanned. You will only get the money for it by returning to a station more than 20Ly from that system. So scan a few.
Detailed Surface Scanner - this is how you make bigger bucks, by fitting one of these it automatically scan any planet you are already scanning with your normal sensors and retrieves more detailed information that nets you more money. I would fit this to help save up for an Advanced scanner.
This scanner cost about 500,000.
These are all you really need to do it, but raising that amount of credits doing solely exploration is going to take a very lo-o-o-ong time and you'll probably get space-sickness and want to fly your ship into a sun.
Fuel Scoop - this is essential for deep runs, refuelling as you go is the only way to explore successfully.
Other things - nice to have and make your ship as light as possible to et the best jump range.
The best power distributor you can afford, the more engine boosts you can do, the more likely you will be able to outrun a pirate.
Buy a power plant that has a low tonnage but will still run everything -you don't need to power weapons - I took none last time I went out.
FrameShift drive, again balance the cost against weight and range.
Thrusters - not really necessary to upgrade, but if you can shed some tons and improve them, go ahead.
You should apply this rule to every module you have fitted.
Final tip - if you do get interdicted by a pirate just zero the throttle and let him pull you out of frame-shift, you can run away easily as long as you can engine boost at least three time in a row (I don't carry weapons when exploring). I'd rather do that than potentially lose the interdiction battle, which will damage the ship and also extend the frame-shift drive cool down period.