There were some interesting studies out of the University of Iowa on giving and receiving advice from spouses. I definitely have struggled with this in my relationships, often offering unsolicited advice. Take a look at this WSJ article that explains the studies.

For me, it took a long time to understand how damaging it is to offer unsolicited advice to women. It's best to step back and listen. Ask probing questions if you feel the need. If she asks for your advice/help, then feel free to give it. Otherwise, sit back, keep your ears open and your mouth shut.