When choosing someone to represent a business or act as a public figure, you have to consider important characteristics that the talent must posses in order to be effective to any given audience. In order to successfully do that, you must have a clear understanding of what it is that your audience yearns to see or hear, with what cadence and lingo, and with what kind of mannerisms?
You must do your research and find out how wide or narrow your age range is, this alone will help you to determine the right age and tone of your voiceover talent for the presentation. You want to relate to your audience, not bore them to death, so it's always suggested to look for someone with high energy that can keep someone engaged. Dry flat voiceover artists might be okay for the occasional joke or comedic touch, but it is not recommended for most presentations. Consider the content that is being introduced when choosing the candidate, this might help with choosing a gender.
If you are having a hard time finding talent for your project, look online in local directories for voiceover talent.
Typically, most cities will have a production association to contact. If your city does not, contact an association from a neighboring city and use their talent directory as a place to start. Another option is to create a casting call for a voice over artist and post it on any online site or social media site that you desire. Ask for examples of their work and be clear about what kind of artist you are looking for... age, tone, energy, and experience.
Do not resort to doing the voiceover yourself because you're stumped on finding someone, especially if you know you're not cut out for it. There's always an actor just waiting for the opportunity to work, it's just about a clear line of communication between the two. Now a-days, there are tons of sites devoted to casting calls and talent advertisement so if you were wondering how to find the right voiceover talent for your next presentation video... wonder no more.