I went full time at work about a month ago; I interned at the company over the summer, and they offered me a full-time job for when I graduate, all the while allowing me to continue my internship into the semester.
My company has an LGBT networking forum; when I first came on I joined the forum and did some volunteer events with them to make friends. A few months of working later I contacted the head of the forum and explained to him my situation. The head of the forum was overwhelmingly sympathetic, and he spoke on my behalf with HR until I was ready to identify myself.
After he spoke with them for a while, they expressed an interest in meeting with me, and I subsequently reached out to them. They were incredibly understanding, assured me I'd have NO problems, told me if ANYONE gave me any trouble to report them immediately, told me I WOULD be using the women's restrooms, told me they'd change my name on everything to whatever I wanted, etc.
In short, they were incredible.
I've had absolutely no problems at work since going full time. As some others have expressed, tech is generally a very understanding industry

I'm a mobile developer and it's a pretty open-minded/libertarian/liberal bunch.