Take your plans! Take any other diagrams or PCV stuff!
Try and find a walk-through checklist on the internet and print it off and take it with you!
Take your time, ask as many questions as you can. Don't feel rushed.. it should really take a couple of hours, maybe more depending on the size of the house, to do it properly. We were there for almost 3 hours ourself.
In each room, tick off the things that are supposed to be there on your plans and lists. Anything that's not there or where it's supposed to be, make note and ask questions about it.
This is your chance to be the inspector. Anything that seems odd.. ask.. anything out of place.. ask.. be thorough!