I've been setting up ecommerce websites for people since 1999, I hope this helps you get started:
Selling online is more than just the mechanics of having a website up and running--its really more about product listing distribution to other sites, internet marketing, social networking, and search engine rankings & traffic. Getting the website up and running is only one of the early steps necessary to succeed.
Here's a task list to get you started:
1. Pick a domain name, register it with http://www.godaddy.com/ . (they're cheap and the #1 registrar)
2. Consult with an ecommerce consultant--I recommend talking with one that can show you examples of their work and proof they have experience, and will do 'free' consulting with you. Do a google search for "ecommerce consulting", "ecommerce web design" -- or look for someone local to you. My site is http://www.webretailgroup.com/
3. Build your site.
a) Hire a web design firm who has a proven ecommerce solution (shopping cart - lists products, cart, credit card checkout) We have a great solution for small-to-larger-scale businesses, that offers A LOT of integrations with 3rd parties; My design site is http://www.nittanyweb.com/
b) Depending on the scale of your business...you may want to DIY - in that case, I'd recommend an open source solution like http://oscommerce.org/ ... if you're not programming/hosting/HTML inclined yourself, then perhaps a solution like Godaddy's Quick Shopping Cart http://www.godaddy.com/gdshop/ecommerce/shopping-cart.asp?ci=9032 .
4. Market your site, build your customer base, and be patient. (but stick with it!)
Ideas for marketing:
Do SEO - Build Organic Traffic - Best ROI
Build your mailing list - opt-in-only - Best ROI
List your products and get links to your site with Product Data Feeds - good list of these here: http://www.productfeeds.org/
Use PPC - Google AdWords PPC / Yahoo Search Marketing / Bing (Microsoft AdCenter)
Use Social Media / Networking - like facebook, twitter, youtube, etc.
you can buy things from Hollister and American Eagle to create this look rather than the preppy look. Diesel clothing is very popular for hipster clothing.