.. using Microsoft word for text, photoshop for cover design and publisher for illustrations in the text. Is that adequate to achieve a decent look for the book? How do I combine the cover with the script to come up with the PDF book.
I am sure you can export the Photoshop image in a format that Word will retrieve. If you plan to keep going in the self-publishing business you may want to invest time learning a "proper" DTP package, such as Scribus.