There are some fabulous hardware devices out there for hardware hacking - it warms my EE heart. Having been out of the field for decades (really, only played with this stuff in college and high school), I'm enjoying getting back into things.
That said, folks who've never studied the material before can still play.
First, get yourself and arduino or similar device.
Then, learn some basic electronics - youtube is a great place to start.
Then, build and enjoy...