Maybe this is a silly question, but I've been trying to salvage parts from various junk I have laying around the house, and I started wondering what the safest way was to begin tinkering with this things without risking damaging the Arduino. Hooking something up that draws too much current is a good way to damage the board eh?
1 RULE, ALWAYS TRY TO LOOK UP THE DATA SHEET BEFORE HOOKING IT UP BECUASE:
that sheet will tell you ho to hook up that device ( relativly )
it will give you power inof like how much power it takes, and yes if something consumes alot of power from the arduino, it can easly damage it!
test motors and sutff like that with batteries first to see that they work well enough for your standards.
and from a personal tip:
never hook up a sensative 2 mm ir led directly to 5v and gnd.... you will heare popcorn cooking if you know what i mean... snap crack pop lol!