Everyone's seen the ads, the spam e-mails, and so on:
"If you can type, you can be a work from home transcriptionist! Anyone can make money from home with just a few hours a day. No experience needed!"
Yeah, right. Keep dreaming. If it really was that easy, everyone would be doing it. However, you CAN get a work from home transcriptionst job, provided you know how to search properly, and are willing to actually work.
It's a crazy concept, I know. Actually doing WORK to make money... 
Seriously, though, finding legitimate work from home transcriptionist jobs isn't difficult, or at least it doesn't have to be. Sites abound that actually list jobs from real companies looking for employees. Craigslist, Monster, CareerBuilder, GetAFreelancer, and so on. All of these sites have freelance and contract positions, including work from home transcriptionist positions. You might even be able to apply for a traditional in-house position and speak to the hiring manager about working from home instead.
If you have experience, that's great. You'll have no trouble finding the perfect position as long as you invest the time to do a proper job search. If you're new to the field, or want to train to be a transcriptionist, you can still find work, it just might take a little longer. With home based positions, many companies aren't too excited to train new employees. However, if you apply, you might be surprised at how many companies actually don't mind training you.
Having fresh people, after all, will allow a company to mold them to their standards without previous knowledge getting in the way. If you subtly point this out when applying, you might get some great responses. People who are already trained are thought to be less hassle, but their previous training might impede their progress with a new company and the way they want things done. Keep this in mind when you get discouraged by all the "previous experience required" ads. Apply anyway. You won't know what can happen until you give it a shot.
Finding work as a work from home transcriptionist might be a little more challenging, but what good is a job that wasn't hard to get? The only great things in life are worth fighting for.
I hope these tips are helpful. Happy job hunting!