I don't know what to advise, except from experience, I purchased JGR's first book and looked thru it once or twice and haven't picked it up since. If it were me I'd go to "Intarsia.net" and follow all the instructions there, which will take you step by step thru making a Intarsia Bear. Once you have completed that you'll have all the basic knowledge you need to make about any Intarsia you want.
That said, I have the following:
Scroll Saw Segmentation (Which has a few Intarsia Patterns also) By Patrick Spielman
Intarsia for Beginners, Judy Gale Roberts
Small Intarsia Woodworking Projects, JGR
Wildlife Intarsia, JGR
Intarsia Woodworking for Beginners, Kathy Wise
Intarsia Woodworking Projects. Kathy Wise
Each of the above have projects that take you step by step from start to finish, They are all excellent books. Bottom line: You can't go wrong with any one of the above. If you can preview the contents of each book, pick the one which has the particular project or types you'd want for yourself. Make sure you keep your first Intarsia to look back on years down the road, lol
AL