About the flirting thing, I'd say there are a few different levels of flirting, depending on the relationship between two people.
The flirting that takes place between two people who aren't going out is generally not sex related, it's just making them laugh, and being really nice. So if you liked someone and wanted to get some gentle flirting going on, you could say note her birthday and get her a present and card, but make sure you're smiling when you give it to her
She'll love the fact that you took notice. Try and go out of your way to make her smile through jokes, gifts (but not all the time), and lots of smiling and eye contact.