Quite possibly the most detailed and complex game ever made, with a
legendary learning curve, a marvelous community, and meticulous attention to even the most minute of details. The world you play in and all its characters, monsters and history is completely randomly generated promising an endless supply of fun.
Probably the best way to motivate a new player to try Dwarf fortress would be reading one of the, now legendary, stories that this game can produce: The story that made me try it is
the story of Boatmurdered, a long read but well worth it. For something shorter and more ilustrated try
Bronzemurder . You can also read
a story i wrote of a massive goblin siege and the battle that followed, backed with a multitude of screenshots. (OP and continued in the top comment)
If you are intrigued with what you have read check:
Lazy newb pack (note - download the advanced version) for an easy install and start. (Also, there are a lot of useful tools included, among them a couple of costum graphic sets, if you cant handle the ASCII)
Also the
extensive wiki is something you will be using heavily. Almost everything in the game is explained in detail there and this will be your most usefull tool. If you got a question, search it here first.
Dwarf foretress has one of the best and most helpful communites i have encountered so far, so you can also use the
forum or
reddit for any advice/questions.
Or ask here, ill be happy to answer.