I'm going to add my voice to the chorus of people saying the interface is awful because it really, really is.
The wiki linked above and that poster's advice to keep it open while playing the game is what I tell any of my friends who I convince to play the game. It is the missing manual and, until the game's interface is improved, it is absolutely vital for starting players.
With that caveat in mind...
Goddamn what a game. Seriously, if there is one game I wish everyone could play, it's this one. And I don't mean just load and scoff at the user interface, but play until they have that moment where they think, 'aha, this is why this game stands out.' And if everyone can't be made to play it, then at least every would-be game designer.
One of the things I like is that it scales well as you learn. And there is a huge variety of different games in it, in a sense : I've felt like I'm playing everything from an Oregon Trail-esque survival sim, to a weird little RPG, to an RTS, to a city simulator. Consider the max population of dwarves you get to be like your high score.
I hope you keep at it. It's been one of the most rewarding games I've ever played.
Oh - and a link to Boatmurdered (http://lparchive.org/Dwarf-Fortress-Boatmurdered/) - this is what I usually would send to friends to let them know just how crazy a game was hidden in those ASCII characters.