Heh, what Dena said. After I had my inaugural aliyah during services (the week after my beit din), I had all of these random people from my synagogue coming up to me going, "Hey, just so you know, we're everywhere," and it's true! I'm pretty open about the fact that I'm a convert, but I even have people I've worked and socialized with for a while now who have no idea that I wasn't born Jewish, mostly because it's not something that comes up all that often. I'm just Jewish. But I can almost guarantee that when you actually take the plunge, so to speak, you'll find out that people you've known at shul for a while are themselves converts.
As far as study time, I studied with my rabbi for about eight months, maybe a little less. My case was kind of weird in that we were working with a deadline, because I was due to ship out to China for my job on X date, so the mikvah and beit din had to happen before then. I had also been learning and practicing Jewishly for a solid ten years before that, so in terms of my Jewish literacy, I was in pretty good shape; my education was geared more toward social Judaism than the religious aspects. My rabbi had given me some essays to write, and it took me a while to sit down and really work through them. Literally a week or so after I sent them to him, he called me in and started planning dates for the beit din. Heh.
I think my timeline worked out pretty well; the only thing I might have done differently would have been to convert sooner in order to give myself more time as a full member of the community before I left for China, but that's pretty minor, in the grand scheme of things.
