While anyone can do voice over work at beginner level, if you want to get well paid gigs you will need to invest in good equipment and training. The voices you hear on the radio or television commercials are experienced actors who have spent years practicing their skills.
Voice over acting is not just about reading out a script, you need to know to put emphasis in the right place, do different accents, different emotions etc. However, it does have the advantage of letting you work from home, so as long as you have a space you can set up as your home studio you can get started.
When you get voice over work the clients are going to want it to sound as good as your promo clip, so make sure you record it in your home studio and not in a location that may have a different sound.
As a complete beginner you can start offering amateur gigs on websites like Fiverr.com to get some experience and feedback from potential clients. If you are worried about spending money on a home recording studio, you can see if you get any interest from clients with the set up you currently have before investing any money in new equipment.
If you are interested in doing voice over work on a more professional basis have a look at the articles below to get some great advice.