Christian Kids Explore Biology by Stephanie Redmond is designed to provide a year of science teaching in the life sciences from a creation-based perspective for grades 3-6. Though it is written with families in mind and can be geared up or down, I found that it is a bit much for younger students, and you should definitely wait until your oldest is in 3rd and up to dive in as a family.
The 35 lessons are designed to be completed at a rate of around 1/week and the book includes coloring pages, printables, hands-on activity ideas, memory verses, supplemental reading lists, recipes, and a lot more. Each unit includes a test as well and the coloring pages for each unit are really spectacular. The main topics covered include: Biology Basics, Plants in God's World, Birds of the Earth, Mammals in the Wild, The Human Factor, Reptiles All Around, Insects High and Low, and Water Creatures.
Bright Ideas Press has also put together a downloadable bundle of all the printable sheets (a separate purchase) which is awesome! That is such a boon to me - much simpler than scanning each page I need in order to get a copy out of the book.
Like other titles published by Bright Ideas Press, Christian Kids Explore Biology is written by a real homeschooling mom, and as a result - it's realistic! I hope I don't come across as slacker-mom here, but this curriculum is pretty balanced - it has straight forward teaching sessions twice a week leaving room for additional readings, delight-driven studies, and hands-on activities. It doesn't micro-manage your entire science schedule for you (though it is slightly scripted and you can just open it and read the main content to your children.
If you want everything and the kitchen sink in a science program, this one isn't for you - it covers the basics succinctly, in a timely fashion without bogging down or drowning you in detail - that leaves room for flexibility and your own expansions if you want to add them. Otherwise, it's a good core program that gets the job done from a creation-based perspective.