You will probably get some unfortunate responses, but for the most part, if your work environment isn't incredibly toxic, I think you'll find that most people won't be phased. Even here in the midwest, we are getting more and more transgender pts. My child is trans; once we went public with this, I of course discussed it at work (in my hospital, pretty much everyone is friends and very open about their lives. It's a small community). I have fielded very honest questions, but not one person has said anything negative to my face. Several people (some of whom I would not necessarily have expected, given their religion and politics) have gone out of their way to show their support. I work in a small community hospital, in a smaller town that is flanked by two cities. This is probably a more liberal part of the state, but it's still a midwestern town. It's actually made me realize how good people are at heart.
I think today's trans/gender fluid is the previous generation's gay. The more people have a face, personality, and personal connection to put with something "strange" "weird" or "unnatural", the more they realize that those adjectives are inaccurate and unnecessary, and a trans person becomes just like any other person. If you are the only trans person in your workplace, you will be spokesperson and educator for the community at large, whether you want to wear that hat or not. I think that is simply the reality of the situation. I hope you don't shrink from that, because the next time they encounter someone who is trans, it will be a simple shrug of the shoulders and a an "Oh, like Kaley". Also, people *want* to be helpful and do the right thing by you. You will need to be very specific when you transition: "Because I am a man, I will now go by the name Kevin, and when you refer to me, it should be by male pronouns. I will be using the male bathrooms/locker rooms. I welcome any honest questions, in the appropriate time and place. This has been a rough road for me, and I thank you all for the support." You give as much info as you feel comfortable with, and you politely decline to provide any more.
Or you can transition and live stealth, which is of course fine, too. It's completely up to you, but if you wish to live stealth you will need to transition before you get your job.
I know this is a long road, but please do the right thing for yourself. And know that you will have support and acceptance. This is, luckily, 2014, and people are honestly more open minded than we sometimes give them credit for. While it may take a few people a while to wrap their brains around it, it is only a very small, minute percentage who will actually be rude or hold it against you.