You can look at the 'classes' section
here.
You can plan your character developement way there, and see which classes have the ID skill.
I don't play CE but I'm sure that the ID skill is just like 1.4: Handy, but not crucial. If you don't get the ID skill you'll simply have to ID things at shops (It doesn't cost much) and have the slight disadventage of not being able to use better equipment found far from shops. Because you wouldn't know what the equipment reqs are and what the benefits (if any) would be.