Illustrate Children's Chapter Book (B&W) and create cover art (full colour)

We have three children's chapter books that require illustrations. The stories are aimed at children 6-10 years of age. They are adventure-based, and basically revolve around three kids who find themselves exploring, discovering and solving simple mysteries. The idea was to write classic stories that can still be relevant to today’s kids, are good to read at bedtime and are of interest to reluctant readers. So there’s no bad guys, weapons, aliens etc, just wholesome fun, a bit of drama and a happy ending every time. Details: We are looking to publish these mid-end April and require 1-2 illustrations per chapter, so a max. of 10 illustrations per book. Illustrations will be in black and white and the style of illustration would be a mix of classic but current so it’s relevant to today’s kids. Looking for fairly simple illustrations, not too much detail required. We like the idea that the illustrations look “sketched” and not too cartoony, but still cool… We’d need a cover produced as well – this would be in color. Book dimensions and other intricate details are still being worked out, but initial thought is that the page size will be 5”W x 8”H.