1. the describe yourself question, which is apparently inevitably in all interviews.
I can tell you how to describe yourself, but I can't tell you how to emphasize what they want to hear, as I have no experience with this process.
If I were you, here's how I'd describe myself:
"I like to make things in my spare time, especially things that involve a degree of creativity and skill, as well as attention to detail in the process. Specifically, I'm into creative writing, cooking, knitting, and drawing. I also enjoy searching for new and better ways of doing things, but still see the value in and draw from traditional methods. Reconciling these approaches in a unique and interesting way is often a theme of my work.
I'm fond of music and instruments, and have devoted a lot of time to studying their properties and seeking instruction in their use. I've even played in my school orchestra/band.
I also make time to invest in social networking sites and personal blogs, because I appreciate the human element and the input of others. I recognize the importance of maintaining and managing ties to people. I'm skilled at balancing my creative work, my social life, and my school work in such a way as to prevent one from dominating and stifling the others."
That's kind of rough, but there's probably a lot you can use in there. That's how I imagine you describing yourself to someone. You should try to put that in your own words, though, as I'm pretty sure my language is a lot more stuffy and formal than anything you'd say.
Oh, and mentioning that you've participated in NaNoWriMo, your School's Creative Writing club, and some other things you've done that relate to your interests might be helpful, too... though that stuff might be better for putting on a form than talking about. Not sure.
2. Should I bring my knitted projects? I do have he schematics of the doll I'm working on right now, and it's mostly finished. I designed it myself, but I don't know if that's what they're looking for.
I would say so, especially if you're going for a Liberal Arts degree. Your interests would seem to make you qualified to go for one. But again, I know nothing about this stuff.