I'd also advise Tamiya. Even if they don't have one you're 100% interested in, it's a great place to start. And make it a simple colour-scheme! No use trying to do a B188 paint job on 1st attempt! Get the feel for it with anything from the MP4-13 onwards. They really improved the ease of assembly after that - esp stuff like the rear wing.
Fujimi's releases seem to be right up there. I have the 126CK and it looks a good kit indeed. Not assembled yet, so can't vouch for that part of it.They've also released several versions of the 126C2 and the mentioned 641/2 (F190). Plus one I'd love, if I did not have the MFH already - the 248F1 - Schu's last ride.
Hasegawa made a 24th 640 (F189) and a 20th 312T2.
So as you can see, if you like Ferrari, you've got plenty to choose from!
Even though it's really really awesome kits, I won't advise starting off with a 43rd kit - it is something to get used to! But I think once it's bitten, it won't let you go, as it did with me. Lots of variety.