Psychology is among the favorite optional subjects of Civil Services aspirants, and as per the changed syllabus, a command over psychology will turn out to be beneficial not only in optionals, but also in GS papers like Ethics (GS Paper 4). Classroom coaching is not extensively available for the subject through out India like History or Public Administration. Having said that, the subject can be covered without any classroom coaching, if the candidate is focused and has right guidance and materials.
Communication with successful candidates who has taken Psychology as their optional subject will definitely help. Listing below certain useful books for Psychology preparation for IAS Exam.