I have worked supply-chain for a few years now ( not video game industry ), just wanted to quote Belisarius and bold some for emphasis.
"A good sales person also travels a lot, to visit buyers and so on, so you would need to be willing to be away from home frequently. Although your job is, on the surface, about selling a product to people, it is also about building relationships--you want to sell them this game, yes, but you also want them to buy the next ten you ship."
Basic PC/Office skills are pretty much a must, working knowledge of the industry you want to work in is of course helpful. Your best bet is to find a company that is hiring for their salesforce locally, or for a sales related position, and working there for a couple of years. Finding a sales job is relatively easy, finding a sales job with the company/industry you want can be very difficult unless you already know people. A good way to break into the industry you want, is to prove on the job that you are able to get to know people and build sales.
Another way to get into sales, is via the purchasing side. Lots of purchasers go into sales, and vice versa. Every industry has its own peculiarities and quirks, but like Belisarius said - Sales is about meeting people and building relationships. At least the type of sales that you would want to build a career out of. When you are scanning those "Outside Sales" positions on Dice.com ( or wherever ) I advise to make sure the product you are selling is needed by potential customers to run their business.
Supply chain sales are the best sales jobs, typically. IE: For games industry, games retailers.. need games to sell. Maybe not your games, but they have to, by nature, buy SOME games. Basically any kind of packaged good or input material is usually a good thing to sell. What you want to stay away from , typically, are selling services. ( unless they are recurring services, like say IT services) But selling say, home remodeling is a different type of sales than B2B supply chain sales.
