going to college

[pellaz]

Why is it imperative? What if the room mate doesn't accept it? Terrible advice I'm sorry to say.
I would just play it by ear, you are a human before you are homosexual so don't let this get in the way of your excitement. You are at college to learn first and foremost, yeah there may be moments where you get the chance to play, but do that discreetly.
The time will come when you will know your room mate well enough to make the decision then what to do. No reason to walk into a room woth a stranger and announce 'Hi, I Jack and I am gay' when all you need to say is 'Hi, I'm Jack, nice to meet you.'.

your room mate will figure it out himself so you will have to deal with the "What if the room mate doesn't accept it?" if there are any issues you should clear up the bad at the start. its not going to get any better by itself.
"Hi, I'm Jack, nice to meet you, i am gay, hope its not an issue for you, if it is we need to do something about it now"

being roommates doesn't mean you guys have to be best friends. ... while we are friendly and cordial to each other, we certainly aren't tight ... You just need to be able to live together.

in the long run all you have to do is coexist but i would never hide.