Barbie: Secret Agent Hints

Gaurds are usually gaurding an entrance to a place you need to reach. If you get too close to them they will ask you to leave. To get past them, get near them and blow your blush in his face. This will give you time to sneak past him.
On the map is a square with a semi-circle around it. This is the caurd and where it can see.

The robot dog is a tool used in this game. To use it, use the same controls as you would use for Barbie. He can distract or lead gaurds away.