A good book, for instance, can be dear (4)
I believe the answer is:
'a good book' is the definition.
'read' can be an answer for 'book' (I've seen this before). I'm not sure about the 'a good' bit.
'can be dear' is the wordplay.
'can be' indicates an anagram.
'dear' anagrammed gives 'READ'.
'for instance' is the link.
Can you help me to learn more?
(Other definitions for read that I've seen before include "Comprehend written words" , "Study (subject at university)" , "Measure energy or fuel consumption" , "Interpret writing" , "examined" .)