For the Game stuff you can show them a short sample fight, that helps clarify a lot.
If you run them through one and make it a social contest rather than a physical fight that will help them see how the 'witty banter' of the books can slot in to the mechanic.
As for the setting, I think it is best to introduce them slowly as your game progresses. Start out with pure mortal or minor talent characters and work your way up from there.
Another option would be to start them out all as one type of 'beasty' you know they would get on with - so if they like 'were wolves' you could have them as a group like the Alphas. That way you only have to clue them up on one aspect of the background, but they get to be 'more than just humans' right from the start.
As they meet new kinds of people allow the Players to generate new characters and swap them into the game. So for example when you group of wolves meet the changeling that live at the other side of the city, a Player could generate one to used as their new character and retire their old one. - or have them hanging around as a n.p.c or back up.
As your characters get deeper involved with the world they learn more about how it works. It is certainly a much simpler approach than trying to get 12 novels into their heads in a few sentences.
It also side steps the 'how far through the novels are we on the time line' question. Also helps if you set it some where other than Chicago, because then you can do almost what you like with out the dreaded "But in book 4 page 67 it says...."
For Con games, when you could easily loose the 3 hour slot just explaining the back ground - I am toying with the idea of 'this is what your guy knows about the world' cheat sheets to be included with each character. That way each P.C. is the expert on their part of the local supernatural community and can answer most of the in game questions (Or choose to lie if they would rather - or indeed be 'miss informed' by 'Daddy' if they are a Raith WC Virgin and confuse every one else whilst actually 'telling the truth')
Given
some folks who have not read the novels and have only small amounts of RPG experience.
My suggestion would be to get the guys that have read the novels to talk about their favourite scenes and why, and use that to set the mood of the game. -
Use the full rules to generate the city with the players so they all have some input, even if it is just an "I think it would be funny if my favourite Cafe was the place all the weirdos gathered on a Saturday to discuss spells and stuff."
Then do the full background based character generation, because that will help them see how Aspects come about. It is long winded, but if people have never RPGed before it can help they grow a character they will engage with. (I used a similar process to this as a creative writing exercise with 7 year olds using the Gruffalo as an example of a character you build up bit by bit. Once people have stopped being self conscious about 'being creative' it does work well. )
Don't over face them with the rule book. let them 'play out' the character with you and then produce the skills lists and powers etc, and find things in there that fit in with the idea. Fate is very free form - if its not in there just make it up.
Same whilst playing, be soft on the rules and let them have fun. There is nothing more likely to put of a novice player than being told that they can't do something when they are on a role - unless you have to explain it will probably get the character killed! Then my advice woudl be to give them teh option - may be they want the noble death scene.