Mui macho, y mui loco! 
Vaya con suertes, amigo, I'm sure!
(Sorry I wasn't on line earlier for the carnage!)
Well, by about this point in time you're at your aforementioned rendezvous with destiny. So, I fully expect you to be coming back with tales of heroism and horror, and a whole new mort of questions.
I'll try to take a guess at some, and address them.
Actually, that shouldn't be disturbing - he's right. For spontaneous spells to be created by players, they need a copy of the guidelines. For you to help them each time is just not practical.
He's not saying that everyone needs a copy of the book, but everyone needs access to a copy, especially those Guidelines for Spontaneous spells - and one copy probably won't cut it.
Maybe you should. Xerox the Guidelines, just those, and cut/paste a handout for your game. Just for reference, so that any magi Player can figure out if his Creo + Ignem is enough to do what he wants, or whatever.
If the Players like the game, they'll buy it. (At $25, that's just a weekend of beer money - and a much longer-lasting investment.)
Once the players have a feel for them, they'll have cribbed notes as to what they can/can't do. Until then, the book, a book, is the only answer source.
Hrmmm, yes, indeed...
First, learn the game yourself. Yeah, too late now, but how often did you have someone ask question and you not be able to answer it? Not a strong selling point.
I'd say, "streamline it" first. Don't worry about Spontaneous, and don't worry about Covenants. Yet. Later.
If you have time, ~I~ would say don't worry about magi - build some "companion" types, non-magic-user Adventurer quality characters, and run a simple adventure scene with them. If they die, it's a learning experience. If they're not right, they can become NPC's. If they like them, they can become Companions - nothing lost, lots to gain.
That way, the players get a feel for the core mechanics, and then can add Magic on to that when they build their 2nd characters, the magi. And while that's happening, they can think about that building. Which will take some time...
(PreGen wizards may be the best call for the first session, so that the Players see what's ~possible~, without having to make mistakes to see what they ~don't~ want to do.)
Once you're ready for CharGen, don't underestimate the time it will take. Lots of distractions for new players, lots of bells and whistles and "what if's" and detours and tangents.
Here's a thread discussing CharGen of Magi for Ars, with different views:
Warn your players, especially the "blow'em up" type, about the diff between being able to learn a spell, and being able to cast it reliably and without fatigue. Especially combat spells. It's an old, old story with Ars, that first time Players take the biggest CrIg (or whatever) they can reach, and then find they can't cast it with any reliability, and when they do the character is soon on the verge of unconsciousness. Smaller*, reliable, non-fatiguing combat spells are better to start with. Big* spells are good for "out of combat", when time (and resting a few minutes between attempts) are not a constraint.
(* "Big" and "small" are relative to the character, natch. After they study, those seemingly huge, unwieldy, unreliable spells will become child's play. If they're willing to wait, that's fine.)
You can also recommend to your players that they read the 4th ed .pdf, especially for the background info & etc. While the Spell Guidelines are not the same (emphasize this!!!), they'll be able to better understand how Mythic Europe and The Hermetic Order are significantly different from your Generic Fantasy World. That, more than anything, defines what a Hermetic Mage can and can't get away with, and can color their choices.
4th Ed download: atlas-games.com/arsmagica/
(Download in the right hand margin, 1st under "Downloads". You have to go to SJG and "buy" it for free, but there's no spam, no scam.)
Waiting to hear how it went!