Teaching my puppy to let me know when he has to use the bathroom

Question
I have a 8 month old golden retriver, he is a pure breed with papers and he is very smart his parents are smart so it runs in their family but any way I taught him to sit in less than a day and its been a week since we got him I belive he understands to use the bathroom when we go out side because if I look at him when he trys to use the bathroom he stops . . .  And every time I take him out ( every hour to two hours) and he is not distracted at first he will pee then sniff to do his #2. So I'm not sure how to train him to let me know when he has to go, I started to make him sit last night by the door while I put my shoes on so maybe he will start to lean to sit by the door when he has to pee.   

Oh one more thing I always use a leash at in the begining of us going out side for him to pee but after I let him off so we can play and run, but he does not always want to go where I want him to go cause he gets distracted by kids ect so he will pull against the leash or try biting it, the only thing I can do to stop him from bitting the leash is bop him on the nose and say NO cause he will not stop. And when he pulls the other way towards kids ect I pull him towards the way we need to go and he getts the hint for a min but I don't want to pull him like that what do you think I should do.

Answer
Once your dog is completely housebroken (knows every time that he goes outside to go potty), then he will start to let you know that he needs to go out.  You can shape that alert by doing what you're doing, every time you get ready to go out to potty, have the dog do something (either sit, speak, or whatever) and then let him out to go potty.  You might want to rethink the sit to be the alert since if you're in another room and he's sitting by the door, you'd never know it.  If your dog is otherwise not much of a barker, you might want to make the alert one bark.

At 8 months old, your dog probably doesn't need to go out every 1-2 hrs anymore.  I would start lengthening the time between bathroom breaks.  If you want him to go potty (pee) every time you take him out, then 1, you need to start lengthening the time and two, if he doesn't go, he doesn't get to go off lead and play.  You immediately take him back him.  He will soon associate going potty with being able to play.  You dog should on defecate as many times as he eats a day.  If you feed him twice a day, he will most likely poop twice a day.  Feed him once a day and he will probably only poop once a day, etc.

My 9 yr old Lab, pees about 3 times a day and poops once or twice (I feed him twice a day).