Help...drain care and teaching

I'm new to home health, and have a new patient SOC tomorrow. The patient had an incisional hernia repair with mesh on right side, and the orders say "drain care and teaching." Patient is being d/c from hospital today and don't see the date of surgery on the paperwork, but the d/c orders were written on the 7th, so maybe it was yesterday or day before.

I worked in OB in the past, and have never even taken care of a patient with a drain except maybe in school years ago.

I have Lippincott's Manual of Nursing Practice, so will read up on drains and hernia repairs there, but most of that will be post-op information and not necessarily home health.

What do I need to know? Any information sources to point me to? What teaching is expected?