Ask her out. The place must be her favorite place or somewhere comfortable to have a chat. It would be great if it's a romantic dinner, but I don't recommend that.
Talk about things you both do while you were away. The topics would come as you have a chat so just talk. Or you can ask her story and listen to what she'd say. Enough, I think.
I recommend not to confess already. Try confessing after asking her out several time until you can tell that she's comfortable hanging out with you. You'll know when the time comes.
Well, facebook chat can be a good start, but make it just like saying hi or just have a little chat. Don't try making a long conversation. It can annoy her, maybe she's busy or something. You don't know what people think through internet. You can have a really long conversation, as long as you want, when you meet her.
I'm not a love consultant, but that's my suggestion. The rest is up to you