To find it definitively:
1. Consult your owner's manual: This is the best resource as it will have a diagram showing the exact location.
2. Use a repair manual or online diagrams: Websites like Chilton or Haynes offer repair manuals with diagrams specific to your year and engine. You can also find diagrams online through searches like "[2007 Dodge Caravan 3.3L engine diagram]" or "[2007 Dodge Caravan 3.8L engine diagram]". Look for the PCV valve in the diagram of the valve cover and surrounding components.
3. Look near the valve cover: With the engine cool, carefully inspect the valve cover. The PCV valve is usually a small, plastic or metal valve with a hose connected to it. One hose will go to the valve cover and another will route to the intake manifold.
Important Note: Because of the location, accessing it might require removing parts of the engine cover or even the valve cover itself, depending on its specific location on your particular engine. If you are not comfortable performing this task yourself, it's best to take it to a mechanic.