I told this story in my First Kiss thread in Hot Topics, but I was really worried that my attraction to guys was something that was just in my head, too. I felt this way until I had my first kiss with a guy and realized "Okay, I enjoy this." Later, I had my first actual hook-up with a guy, and it really wasn't that good of an experience. . .I was a little lost, but I figured "Okay, so I didn't HATE the experience, so I at least know i'm not straight. . ." Soon after that, I met a college guy I hit if off with, and learned that I really, really enjoyed making out, cuddling and sucking a guy's dick if I was comfortable and liked him. We even talked about going out, and I think it was solidified in my head when I realized "Okay, so I enjoy kissing and having sex with a guy, and now I know that i'm capable of going out with a guy; that it can go to the next level. . ."
But I didn't know ANY of this until I took that chance and had that first kiss.
You've said the attraction is there, but you really aren't going to know until you experiment for yourself. You don't have to go any further than you're comfortable with at the very beginning, but a kiss is a good place to start. Wait to find someone who won't rush you into going further than that.