i leave a bowl of food for my dog all day long (dry food)..
but im wondering, is it better to give him seperate meals..or for him to decide when he is hungry?

IMO, its best to feed 2-3 scheduled, premeasured meals. This helps to keep defication on a regular schedule and ensures that he is not over or under eating.

I leave a bowl full of dry meal all day and keep adding to it. Must say that my dogs have access outside when they want and someone is always at home. I don't consider my dogs fat but just think it is better for them to feed when they want to rather than waiting for me to make them a meal.

I was told by the vet that it is best to give accurate amounts of food on a regular basis; not to constantly leave the bowl full. Some dogs will constantly eat, which is not good.

Ive only had chester two days..and in thinking maybe thats why he doesnt eat much yet..we have been leaving his food out all day (but I do notice how much he has eaten) i put in one handful to start then when that was almost gone I put in another (that was HOURS later)

but I think I should just give it to him at certain times for now (at least until I see exactly how much he is eating)

he seems to drink more than eat..he pooped twice yesterday and once already today though so he must be getting enough food
as for water im trying to figure out if I should give him limited access to this (just so he doesnt pee so often (and such TINY puddles) LOL

I fee our once a day usually and never fill up the bowl till it is empty. My dogs aren't overeaters though, so that might be a diff't story.

Actually, I leave my dog food out all day and my dogs only touch it one time during the day. So, its there if they want it, but they chose to eat once a day, usually in the evening. They are huge water drinkers and my one dog likes bones more than anything, so maybe that has something to do with it too, I'm not sure. I would certainly change that real fast if one or both of them decided to eat on a constant basis because that is just unhealthy for them.

I free feed my dogs, meaning there is dry food available all the time. I also fix them a mix of dry plus a spoonful or so of canned once a day. I have just recently started doing that and they all seem to love it. I have 8 and none of them overeat. I have read that its better to free feed (always available) because when you limit the food to just once or twice a day they will gobble it all up whether they really want it then or not because they dont know when they may get any more. They also get treats a couple of times a day as rewards.
Occasionally they will get a table tidbit but not often. I also occasionally add some cottage cheese or some egg to their dish.
I leave out 2 different kinds of dry food so they have a bit of variety. They all seem to be healthy, happy, and thriving. :-D

Bo gets 3 cups of kibble split twice per day (2 cups in the morning and 1 cup at night).

My vet also recommends 2 pre-measured meals per day. She said free feeding has a very high correlation with overweight dogs.

I left my dogs dry food out all the time, and because it is always there, he no longer conciders it special enough to eat. Not with us eating chicken. Usually I add some chicken into his dog food, and he eats it all.