Sorry I've posted this before - I've updated this

Hey guys,
Basically there's a girl in one of my classes, I was sat next to her on the way back from college and didn't know her. I saw her put on the same bands I was listening to twice in a row (my iPod was visible to her) so I struck up a conversation and now we go to college together. Anyway, I do like her - this isn't some oneitis crap I've had that (how horrible?!) and we just generally talk about our many similar hobbies / subjects. I know to progress I've got flirt / kino and stuff, but how do I go about implementing this subtly? I'm trying to talk to as many girls as I can just to improve my confidence but I am by no means leading them on.

Any advice by you guys is much appreciated?

Shall I simply ask her out somewhere we've talked about? (Cliche?)
Part of me now just says 'nothing matters as much as you think it does' get on with it - stop thinking so much. Do you agree with that view?

I'm generally a bit nervous, but I've been told it doesn't come across. Thanks in advance - sorry if this is in the wrong category.

I'm having a party soon and invited her but she said she might be babysitting. I text her saying she could bring a few friends but she hasn't replied. Have I fucked up? Shall I just leave it and play it cool. Have taken your advice guys and am making an effort with other friends that are girls.

I texted her to say she could bring a few friends if she comes, but she didn't reply so I blanked her in class today and she didn't come over to get the train home with me although I did get it with another girl in the end. Have I fucked up completely?

There are several questions, so I will quote and answer them one by one. (There seems to be some issues with the editor here in my browser, so I can't quote correctly, so I'll stick to a Q/A notation).

Q: "I know to progress I've got flirt / kino and stuff, but how do I go about implementing this subtly?"

A: You have already done what I would do - invite her to something fun like a party. You need to have fun experiences with her, so that's the right way to go. About kino, you should start small. Just touch her shoulder or her arm when you want her attention. Touch her on her back when you want to lead her through a door or something. That is friendly and subtle.

Q: "Shall I simply ask her out somewhere we've talked about? (Cliche?)"

A: Wait until you know whether you have blown it or not. Have your party first. If she's not into you, you should let her go and give your attention to someone else.

Q: "Part of me now just says 'nothing matters as much as you think it does' get on with it - stop thinking so much. Do you agree with that view?"

A: Yes, but I know how hard it can be when your mind is occupied by one person. Try to get an emotional distance to her. Maybe she isn't worth your attention in the first place? Did she do anything to get it? She needs to work for it!

Q: "I'm having a party soon and invited her but she said she might be babysitting. I text her saying she could bring a few friends but she hasn't replied. Have I fucked up?"

A: No one can tell whether you fucked up from what you have written. There may be several reasons why she hasn't replied. If you have sent her an invitation, you should only try to contact her one more time, just before the party and check whether she will come. If she doesn't answer that, ignore her.

Q: "Have I fucked up completely?"

A: If she didn't even try to talk to you about your invitation, you must have fucked something up. Maybe she is just an asshole. I suggest you forget about her. She has to deserve your attention. Make her want it by making yourself popular among other people, both guys and girls.

I usually get the train home with her yesterday, but she looked round to smile at me and say hello in class and I just looked over her head at the stuff on the board. I know that's quite rude, but I felt like I should be a bit offish. She's very nice, and we talk a lot when we're together. Anyway, she usually comes to find me for the train but didn't yesterday, I did perhaps look a bit far away and offish, then I got the train with one of my best friends - who's a girl - do you think she might have thought that she's my girlfriend? My friend kept looking down the aisle to try and see her and apparently by the end of it the girl was pointing at my friend. Very awkward.

Shall I text her and be like; "Hey sorry I was in a shit mood yesterday" or does that make me look needy and like I've thought about it?

She asked me who I hanged round with at college and I just said 'just different people all the time' as I basically am on my own, though I do have a social life outside and in lessons. I need to sort this out, I'm working on it.

Any general advice on that? Specific advice is welcome too!
Cheers for all the advice mate, just thought I'd update it.