If you're looking to try your hand at a virtual existence, IMVU is the world to go to. Start out by creating your very first account on IMVU. See about building your avatar.
IMVU is a 3D avatar chat, instant messenger, and dress up game. Chat in 3D, hang out and have fun in thousands of animated 3D rooms. Create the experience you've always wanted by shopping the catalogue, designing and decorating your own virtual world, and making and selling your own designs. Get help with all of your IMVU avatar needs with these IMVU tips and tricks! This video tutorial teaches you how to create an account and avatar on IMVU (10/30/09). If your a total beginner to this, you might find this helpful.
Description of the application directly from IMVU:
"IMVU is a social network and 3D virtual world where millions of people meet, chat and have fun in animated 3D scenes. You can shop and dress up your avatar with your own personalized look, design and decorate your own 3D space, and connect with new people from around the world. IMVU is easy to use! Just download the FREE software onto your computer to get started."
You can even connect your IMVU avatar with Facebook!
Search WonderHowTo for more IMVU 3D Messenger, IMVU Home Pages, and IMVU Catalogue tips and tricks!