Brad in Utah says:
I've recently started adding voice overs to my videos. I found fiverr.com and have been able to get excellent professional voiceovers made for $5 for 125 words and around $5 for each additional 100 words. I have used this woman that does both American and English accents with really great results. Also, I have used fiverr.com for motion graphics and logos.
They have a huge variety of services you can use. Check out Fiverr.com.