Being shy and finding a job?

I just graduated from college a year ago, and am looking for a job. I've decided I want to work in a library, and I plan to go to school for an MLS within the next 2 years. I applied online for positions at libraries in my town, but I didn't get chosen. My mum thinks I should go visit the library up the street, tell them about my career plans, and ask if they have openings. If they said no, I'd ask if I could leave a resume and be kept in mind for the future. My problem is that I'm really shy and I don't talk about myself very easily. I tend to be kind of stiff in social interactions because I get nervous. Also, I am afraid that the librarian will think I'm bothering her because I already applied once and got rejected, or that they'll think I'm just a stupid, overconfident kid. How can I overcome my fears and get down there? How can I get myself to relax and seem more natural?