One of the best resources you can find for information about voiceover is Edge Studio. They have lots of free stuff to help you start figuring out if you should invest in more training. I suggest signing up for their newsletter. You should find a link on practically any page on their site to register for one of their newsletters. Visit Edge Studio.
The article that caught my eye this morning was “Defining your Voice Over Type” and Finding your Niche,” by Kristin Price, one of their instructors.
She offers some solid practical advice on figuring out where you might fit in this business. Not surprisingly at the top of the list is LISTENING. This will be one of your assignments all through the semester. We are starting off with commercials, but as you noticed from your homework assignment over the weekend, you needed to think about as many different areas of voiceover as you could. This requires paying attention to the voices around you.