Hi Kaitlin, these may be a few good places to start:
- Introduction to Philosophy: Let us know about adoptions or adaptations (Christina Hendricks)
- Adoption Guide, 2nd Edition (BCcampus Open Education)
I think for your OER, a feedback survey may be more valuable — you can take a look at the links collated in the “classroom review” section in our review and feedback handout. The pre and post-surveys (especially the qualitative questions) from the Textbook Evaluation Toolkit may offer some inspiration as you’re putting something together.