Here's a tip for holding open a stiff new cookbook.
When I need to free my hands for cooking or baking, and I want to hold my cookbook open to a page, I usually use a weighted leather bookmark that is designed for that purpose.
But if my book weight isn't handy, I use a small glass cutting board . The one pictured is an inexpensive one that Maggie bought for serving cheese. It's clear glass, so you can read the book right through it. It's not heavy, so this one won't break the spine of the book.
(The image is garbled on purpose because I didn't want to post a detailed picture of someone else's copyrighted work. So you'll have to take my word for it that the text was quite readable.)