POI - Garmin Street Pilot c530

I recently bought my first GPS and love it! I don't get lost anymore. I was intrigued about POI and finally managed to get one downloaded. I was disappointed to find that most POI seem to relate only to radar traps or red light cameras.

I live in Aurora, ON, Canada (near Toronto) and love to go for day road trips with my puppy (she's 13). Does anyone know of a POI that would have local POI for parks, conservation areas, walking/bike trails, water fall tours, ghost towns, etc?

Also, since I usually manage to stumble upon a great spot or two while I'm out jaunting around, would I be able to start a POI for this kind of thing and how would I go about doing it?