Outpatient coding-what books do I need?

You need the ICD-9 CM for the diagnosis and the CPT for the procedures. You will not use the ICD-9 CM vol 3 for procedures for outpatient coding.
You may also need a HCPCS level II book, I find helpful as well the Coder's Desk Reference for procedures/diagnosis as well.
You do not use ICD-9 CM procedure code (Volume 3) for outpatient, those are for facility inpatient only.
You use CPT code for procedures.
If your doing speciality coding I highly recomend the Ingenix Coding Companions. I code for four specialities, and these are my life lines.