Well, not being immune to those butterflies myself, I suggest you remember this. Heather, (whoops, I mean this girl) is feeling the same way you are. You both want this to work, so let it work. Realize that the other person is just nervous and realize that they are nervous because they care about you so much and they want to be perfect for you. So take their initial akwardness for what it really is, and try to get past it.
Here are some ways of unrooting the akwardness.
Use IceBreakers like how bout them sox, or politics, or how porn degrades women(if I know "this girl" she really like that one), or hell, bring murcie up, he's quite a character. Or when you start feeling a little weird, turn it into a joke, tell her "yeah this is alittle akward right now, i dunno what to say" you both can laugh it off and turn it into a positive thing.
So remember, when you get that queezie feeling in ur stomach, that ur striking out with...... this girl, she is feeling the same way. Be honest, be urself, do not be afraid, and use protection.
I've said my peace and I'm out.