Thanks to everyone who weighed in on my "when to tell them" dilemma. I decided to give my company one month notice before my final day, which I did earlier this week. I really couldn't have asked for it to go any better. I was pretty nervous; it took me 2 weeks to draft the "perfect" resignation letter. I've worked at the company since graduating from college and I've developed a really strong community. Most of my friends, the people I hang out with on the weekends, are from work. In short, work, even outside of work, is a big part of my life. So, I approached the meeting with my manager with both sadness and apprehension.
When it came down to the actual talk, my manager was a bit surprised, but very encouraging. He expressed a bit of jealousy and told me that I should follow my dreams. It was a more emotional and whimsical response than I expected from my technical-minded boss.
As news has started to spread throughout my area, all of the managers have stopped by and expressed congratulations. They've also been really accommodating in terms of finding me an assignment to fill my time for the next month; I actually have more on my plate now than I did a few weeks ago! So, I guess I just worried a whole bunch for nothing. :)