All books need good cover pictures and if possible, drawings of the main characters to help bring them to life for marketing and reader interaction. These elements can be the difference between making your novel stand out against the thousands of other competition titles in your genre. Luckily for me, from a referral of a friend, I came across Daisy Spiers, who has drafted the pictures of my characters and helped to bring Salvation to life (you can see her handy work on the Artwork page).
The process of creating book covers and character artwork from scratch can be time consuming, so you need to factor this into the timeframe for your marketing leading up to the publication date. However as I mentioned, anything that can make you stand out against the vast number of titles already in the market, is most definitely worthwhile investing into, and a few minutes spent on Guru is a worthwhile investment!
Don't be afraid to have a look who is out there, and how they can help you gain maximum exposure for your novel!