Just the Basics: Artists' Alley
Artists' Alley is the region (most often) of a convention's merchandise room that is devoted to mainly local artists. Often these artists have original work in addition to amazing renditions of characters we all know and love.
Sometimes, you can even commission a piece of art from an artist at a convention. The especially exciting thing about Artists' Alley is that it's usually made up of up-and-coming artists, as big-name artists can often score a spot in the Dealers' Den. Visiting Artists' Alley as a consumer is an awesome way to discover and support some amazing new artists. Don't fret if you didn't budget enough cash to buy anything other than that Soul Eater plush, because most artists will also sell their work online or at other cons.
Make a point of visiting the tables with art that peaks your interest, because most of the time artists are ready and willing to talk about their work, and show you other pieces that you may like. Artists will often offer special deals to people who take the time to visit with them and admire their work. Personally, I try to buy at least one piece of art at every convention. Often, the artists will offer amazing deals if you buy multiple prints of their work, so I get reeled in to buying even more than I intended because it's just. So. GOOD.
It's important to keep in mind that most artists are at their table from open to close with minimal breaks, so be respectful, polite, and excited to see them as they are to see you. Don't forget to get a card with their information on it. You never know if you'll want to add to your collection!