I live in Central Texas. Nearby, there's a small business development center that helps small business owners or people who are thinking of opening a small business. If I were you, I would see if you have something similar nearby, someone who can help you think of all of the questions you should be investigating at this time.
I buy most of my fabric online. In theory, I want to support our local quilt shop, but there are a couple of things that hold me back: One, their hours are pretty limited. For example, they're not open on Sundays. And two, and probably more importantly, the people who work there don't always seem excited about having customers. There have been times when I've waited five minutes while the employees finished a conversation with each other. I took a class there, and the employee who taught the class got annoyed when I didn't want to use my Gingher scissors to cut a piece of paper. Just weird little things that make me feel more like an imposition than a welcome customer. You should train your employees to ask quilters what they're working on, and to be excited about it.
When I do go to the quilt shop, I usually have a pattern in mind, so I'm looking for fabric. If I need red fabric, I want to see a wide variety of options. You'd probably need to stock lots different fabrics of each color. While traveling, I have impulsively bought precuts--jelly rolls, charm packs--and I imagine these are good moneymakers for the businesses. (I hope they are!) So it would be good to have some of them on hand.
It *is* possible to be very successful with a quilt shop, even today. Look at Missouri Star. They started as a small quilt shop and are doing amazing things. They opened in November 2008, according to their website, when the economy was at its lowest. This can be done. If I were to open a quilt shop today, I would plan on selling online, as well as in the store. Find as many different revenue streams as you can.
We went to North Carolina this summer, and I was surprise when I went into a few quilt shops and found only quilts for sale, but not fabric or thread or other sewing supplies and quilting accessories. I love that they sold quilts, but as a quilter, I wasn't interested in buying someone else's finished product. If I were you, I would cater to both types of customers, those who want to buy quilts, and those who want to make quilts. You could also do fun things like, "Featured Quilt of the Month," and have your customers send in pictures of their finished products, and then choose one to feature on your website or Facebook page.
Good luck, whatever you decide!