Hi K.!
It sounds like you already have an idea here - small shops, website, word of mouth are all great and can easily work together. And as the private owner of 2 businesses myself, I will tell you that it does NOT have to be expensive to get started...Just take it one step at a time.
When you consider a name for your business, check first to make sure it isn't already copyrighted by someone else.
Website is a definite because you can display your work (even what is already sold, murals you've done, etc). You want to put your web address on your business cards, flyers, etc. I highly suggest Wordpress for a DIY website. You can do a ton with it, looks great and it is easy.
Social Media - start a FaceBook and a MySpace- invite your friends, have them invite theirs ect. Place photos out there, talk a bit about it, etc.
Business cards are great, especially if they are creatively done. Of course you will put your web address, email address and phone number on them and give them to absolutely everyone you know and those you don't...leave with the tip at the restaurant, leave them at the counter in stores that allow it- some coffee shops and even some convenience stores allow this.
Also, any community board you can find (I know my grocery store and local pool have this) is a great place for a Flyer. Flyers are easy and you can make them yourself and print them on regular paper - with your talents, that should be a breeze for you.
Remember that when it comes to selling ANYTHING...appearances do matter - put plenty of time into your name, logo, slogan, etc and have great looking cards, flyers, and website.
Boutiques/Specialty shops often are willing to sell unique items for commission - if something sells, they get a cut...this is actually a great deal because it doesn't cost you up front. Just make sure you take plenty of awesome samples they can see/touch and be prepared to sell them on the idea when you walk in the door.
Before you get started on anything, it is a good idea to decide what your short term goals are and make a step by step list of exactly what needs to be done to accomplish them. As for long term goals, at least attempt to define them but don't try to jump that far into it just yet.
Good Luck to you!!!!