Alright, the day is nearing (it's tuesday now where i live want to ask her out tomorrow) so I need to get this sorted out.
Thank you everyone for the help, advice and tips but i will need to arrange all your points into just a few sentences to say to her.
So, basically:
1. Wednesday is probably the only time I can speak to her completely alone without intereference from friends/others.
At my school there will be assembly. After lunch you must return your bags to form/home room then walk to assembly. We often cross paths at this time (she's in same homeroom) and she is most likely to be by herself.
If that doesn't work out i have one other opportunity when we are walking from assembly back to homeroom to get our stuff again. So basically this is my best chance of asking her out without interference, and if i dont do it then i may have to wait yet another week.
2. So, taking this into consideration: Is it still too early to ask her out? I started liking her 3 weeks ago today and in that time have talked to her, developed a bit of a 'friendship', etc. Or should I wait ONE more WEEK.
3. When I actually ask her out, just what DO I say? Please read the other replies and take them into account.
Basically I have a few ideas. Strike up a conversation with her than mid-conversation:
"Can I ask you a question? I noticed we barely have anytime to talk about our stories. I mean it's mainly mine but I want to talk about your stories as well. (pause, looks her directly in the eyes) I was wondering if I could buy you a coffee sometime, say Tuesday afternoon at 5pm. Maybe we could meet somewhere downtown, sit down, have a nice chat. What do you say?"
If she asks me "Are you asking me out?" I will: "(look her in the eyes, smile slightly) Maybe, (wink). Why, do you want me to?"
Then we'll just have to see what happens.
Please offer any last guidance or advice if you disagree with anything...Thank you all as this has made me rethink my plans and hopefully succeed...