Well, there's this girl I've known for about 5 months now, and well, since the moment I saw her I've had like a major crush on her.
We chat a lot, and occasionally talk on the phone.
Her best friend told me she told him that she started liking me back a while ago, but that she wasn't so sure.
And I'm kind of sure about this, since talking to her today she told me some guy told her he was jealous of me.

We weren't able to go out this past weekend, but we talked on the phone this Saturday, for like hours. But this week I'll tell her that we should go out this weekend, to finally tell her how I feel about her.
She also confessed to her best friend that she likes me back this past Saturday, saying that she really does like me back.

The thing is, I've never really had a girlfriend, and she's had one or two boyfriends in the past, so I really don't know what to say when I tell her, or even how to approach her with the subject.

Just Be Like * Umm.. Do You Believe In Love At First Sight * If She Says Yes Then Tell Her * Well , Ever Since I Saw You I Like You And I Still Do * It Will be Awkward At First But If You Really Like Her And It Sounds Like She Likes You Then Give It A Try And If Your too Shy Or She Can't Make It Then Tell Her By Text Or Facebook

Just be forward with your feelings and tell her. Tell her you would like to date if she is interested and let her take it from there. It will either be a yes or no. There is no trick to asking a girl out and it doesn't matter if she had boyfriends before you. You are you.

The OP posted almost a month ago, hopefully things went well.

But for future reference, you don't need to make anything up or prepare lines. Just say what you feel. Be sure that you are being honest to yourself and to her.

If you don't know how to bring it up, then be direct. Wait for an opening and just tell her that you have feelings for her.