To the OP, definitely not a stupid question. A biking message board I frequent has been having a similar discussion.
Always best to find a jogging path or a trail. I don't have safe roads or sidewalks were I live so I have to drive in my car to go for a run. Sounds silly I know, but it's the safest way.
I do most of my jogging and biking on a local Rail/Trail. So, I agree that they can be the safest way. That being said, you need to follow the rules, both written and unwritten. Most of them come down to remembering you're sharing the trail with people going multiple speeds in both direction.
1) Unlike on the road where you run against traffic. On the trail, you are the traffic so you stay to the right (at least in the U.S.)
2) Unless the trail is extremely wide, you wouldn't walk or run more than 2 abreast. On most trail, I've been on, that third person will be across the, sometimes imaginary, center line impeding people coming the other direction or people trying to pass.
3) Signal to the people ahead of you your intention to pass. Tradition says you call out "on your left" if you are passing on the left, or "on your right" if you are passing on the right. But people unfamiliar with tradition will sometimes move that direction right in front of you. So, I normally just call out a friendly "hello".
4) Watch your kids. Fortunately it hasn't happened on the bike yet but while running I've had a kid dart in front of me and I've needed to do some fancy footwork to avoid a collision. Not easy for someone 320lbs.