What to do?

Why is it that every time I think I can go ahead and like someone I throw myself for a loop with the whole emotional thing? In other words, every time I start to like someone I try to hold off and get to know them as friends first, but I inevitably wait too long and one of two things happens: a) I miss the chance to ask them out and we're stuck in the "friends" mode for ever or b) as I wait I happen upon someone else who sparks interest and am lost as to which girl I should persue, if either.
This is a predicament that is not easily solved. On one hand, I've known one girl longer than the other. We have talked a fair amount within the last few months and I have even asked her to attend a wedding with me as my date. She is funny, interesting, and good looking to boot. On the other hand, this other girl knows more of my friends already, is cute, funny,and it's easy to be comfortable around her and talking to her.
So what should be done about it? What should I do as a responsible male not wanting to hurt anyone's feelings or be hurt in return? I have no idea. I haven't told either of them that I'm interested, but both of them might know just from conversation. I really cannot tell whether or not I'm being obvious in my conversation as to how I feel towards someone I like.
Anyhow, I'm frustrated because in some alternate reality I wouldn't have to make such hard decisions or face such difficult problems.