Here's a bunch of great links I've come across lately.
Timothy Adam Designs - Article on increasing your Etsy traffic (many of the tips will also work for other selling venues as well).
Etsy Marketing - You Can Sell More, Here's How. Site all about marketing your Etsy shop. Some really great articles here.
Allover Art: Tuesday Tip - $100 Facebook Ad Credit Try out facebook ads for free, $100 gives you plenty of time to play with the ad service. This is legit, I gave it a try.