Slug Identification for the Chicago Region (links)
These are some general tips and links I use to help me identify slugs
Person Inat to confirm slug observations:
https://www.inaturalist.org/people/cedric_lee
Here is a good guide with pictures for some basic understading of slugs and their families
https://www.npdn.org/system/files/WPDN%20Slugs%20of%20Kentucky.pdf
A good to know slug family guide
https://pdfs.semanticscholar.org/569f/d0c2c4d2f0ab37bacb292b498cfc4c4a8fdc.pdf
Document listing the Taxonomy of slugs of North America:
http://northamericanlandsnails.org/publications/AMS_Workbook_KEP_FINAL.pdf
Taking care of slugs and snails while in holding
http://velvetdragon.com/cyberslugs/pets.html