There are many different types of illustrators: children's book illustrators, science fiction illustrators, comic book artists, fashion designers, theatrical and costume designers, animators, video game artists, toy and game designers, product and industrial designers, fantasy artists, scientific illustrators, muralists, fabric and pattern design, greeting cards, scenic designers, prop makers, and many others. Illustrators may work in traditional drawing and painting, sculpture, multimedia, and digital media. The most successful illustrators often work in several different fields, along with creating and marketing their own personal work. A successful illustrator is constantly refining their skills to reflect the changes in communication, technology and the rapidly changing needs of visual communication.
This book is the single most important resource for you as an illustrator and I highly recommend it: The Graphic Artist Guild Pricing and Ethical Guidelines, affectionately known as GAGPEG.
I hope you find the information, links and resources on this website to be useful on your quest into illustration. Good Luck!