Tools are a necessity & if possible, dont skimp on them. I have been lucky in that being a retired electrician i have many tools to use. But i still needed some upgrades to the ones i have. "Maybe i should say treats"

I will put a list opposite on ones i have been happy with & lots more on the Link's page. 
   To start on the electrical side, some decent pliers & cutters along with some decent screwdrivers of all types & sizes. Worth also getting a set of watchmakers screwdrivers. 
If you got some electronics to do. A decent adjustable soldering iron is a must along with a digital multimeter.
Also use a good solder & plenty of good quality flux.
   Because of the framework i was making for the razed track base from "Scaffold", i treated myself to a metal cutting chop saw "EVOLUTION R355CPS240V 2200W 355MM ELECTRIC CHOP SAW" & a MIG welder as i had at least 150 cuts on the steel tubing & around 20 scaffold tubing brackets to make up for the planned corners, & wasn't cutting this lot by hand.  
I also purchased a 6" ground auger to hand drill down 600mm/24" for the main scaffold support poles. These i am sleeving with 50mm waste pipe & hopping Postcreate will do the job of holding them in.
I did look at a petrol version at £160.00, but this was the better choice at £40.00 & gave me some exercise with having to get past stone, bricks & tree roots in the ground. A petrol one would not get past these items untill you have removed them.