You are starting off on the right foot by being honest. Just know that you won't always feel comfortable with poly because you're new to it, but that is to be expected. You will likely have some old ideas/beliefs about relationships that come from monogamous culture, but if you talk about it, examine your thoughts and feelings, and stay true to yourself, you should be all right. I think you (and solos like you and me) have an advantage in some ways. While we don't have a spouse or established primary partner to fall back on for security, we are able to establish our boundaries, make choices for ourselves, and live on our own terms -- of course, with consideration for all involved.
I would also like to say that, because you are in the midst of feeling a rush for two new relationships at once, just think of the word "balance." By that I mean... be sure to remember to be available to yourself and take the time you need for self-nurturing, your own interests and goals, hanging with friends, and family, and be on the lookout for any times when you might "run" to be available for one or the other of your guys when you really need to get other things done for yourself.
And have fun!