newbie help needed with leash

Some general tips:
 
You can get leashes in which the bottom part is made of chain, not fabric. Not quite so fun to munch on.
 
Many trainers will tell you that loose-leash walking is one of the most difficult things to train a dog to do. I approach the issue this way: Pulling on the leash has the appearance of getting a dog where they want to go. It's self-rewarding. The trick to stopping this behavior is to stop making the pulling rewarding and start making staying closer to you more rewarding than pulling could ever be. Some very common ways to do this are:
 
1. Be a tree. When the dog pulls, you stop walking. This is really difficult for the first few days because it takes a while for a dog to understand the causal relationship here. You may at first get no farther than the end of yoru driveway, but it's really important that the dog NOT get the opportunity to pull while this training is happening. That means, if it takes a half hour to get to the end of the driveway, that's the walk for the day. Provide off-leash exercise in some other way to replace a longer walk.
 
2. The "Penalty Yard". This is along similar lines to Be A Tree, except when the dog pulls, you turn around and walk the other way. When the dog begins to pull that way, turn around again and walk the other way. Repeat, repeat, repeat. As with above, you may not get far at first, so provide alternative means of exercise.
 
3. Behold the Power of Cheese. I've never met a lab who wouldn't sell their soul for a treat. When the dog walks with you rather than pulling, reward. When the dog begins to pull, apply the first two suggestions above.
 
I'd try those things first, before investigating no-pull walking devices. If the dog doesn't show progress after a week or two of consistent training, then more drastic measures may need to be taken. But all those no-pull walking thingies are designed as temporary training aids, not as permanent solutions, so at some point this dog is going to need to learn to loose-leash walk on a regular collar. Might as well start with that and then see how it goes.

I'm going to echo all of the above by houndlove (these are the EXACT methods I use with my dog and it's working great!  Still aways to go before I'd try her without the gentle leader, but we've made a lot of progress towards loose-leash walking over the past month), but I wanted to add a few things that address the leash-biting in particular. 
 
My current dog, a pitbull puppy, and my old dog, a golden-mix, both are/were really into chewing on their leash.  With my old dog, we suspected it was more of an issue that the dog liked walking with something in his mouth, since he really didn't tug on the leash while holding it in his mouth (don't know if this is really true, but we had been told that this is common with retreivers, so maybe it's the case with your lab).  We simply found big, hearty sticks the dog couldn't destroy (with no pointy ends!) and let him carry a stick in his mouth while being walked.  Problem with solved. 
 
With our current dog, Scout, this same method worked, but only partially (she does seem to enjoy a stick in her mouth while she walks, but the leash was often more enticing than the stick).  We thought it might be a dominance thing (like houndlove said, pulling on the leash makes the dog feel like you're going where the dog wants to go), especially since she would pull and jump while doing it.  So, before we even TRIED getting her to do loose leash walking, we let her know that biting her leash was unnacceptable.  Similar to houndlove's method but with a release command, like this:
1. Dog bites leash
2. Stop walking
3. Give "release" command
4. Wait a moment, reward for releasing
 
We'd then resume walking, and keep repeating the above steps until she got the hint that we weren't going to walk her if she wanted to keep up the leash-biting thing.  She still does it from time to time, but we've nearly eliminated the behavior.  We also no longer reward for releasing if she does it, resuming the walk seems to be enough of a reward.
 

houndlove is correct about Labs...they think with their stomachs!!! Mine does anything for a treat! Also, get yourself enrolled in a training class...it is very helpful and you have a trainer at your disposal. If it makes you feel better...Marley and I did 3 obedience classes and we just passed the CGC. He is 1 year 8 months.

Some dogs develop a taste for tabasco, LOL.  Try smearing a bit of Vicks Vapo Rub on.  If that doesn't work, sprinkle some Alum on it, too.  Carry something, like a hard rubber toy to substitute for the leash.  Young Labs are just so orally fixated. []

Thank you so much.  He is improving already.  I've taken him out twice since I posted.  The "tree" response when he pulls really does seem to make an impact.  I am also rewarding him when he responds to me and drops the leash.  We didn't get far down the road but the second time was a little farther than the first.  I will continue to chip away at this.  He loves to be out and there are times when the leash will be absolutely necessary, never mind just fun.

Not sure what leash you have but the "double grip leads" with the "traffic handle" are great to use too for helping t o control a dog better and also to keep them close to you because they have an etra handle that is just above their collar. Usually you can find them at Petco or petsmart...here is what they look like:
 
[linkhttp://www.petco.com/Shop/Product.aspx?R=3829&Nav=1&N=0&Ntt=leashes&sku=811858&familyID=6316]http://www.petco.com/Shop/Product.aspx?R=3829&Nav=1&N=0&Ntt=leashes&sku=811858&familyID=6316[/link]&
 

Actually, I am using an old chewed up leash from the previous owner that now smells like buffallo wings.  I didn't want to use the new one I purchased for him until he stopped munching this one.  The one I bought is a typical 6 ft long Lupine brand leash like I used for my last lab.  If I don't continue to make gains with my new pal I'll consider any option, including the leash with the extra handle. I am open to suggestions with my very stubborn but even smarter boy.

Yeah, the leash with the extra handle works well.  Scout gets very excited when people and ESPECIALLY other dogs walk by, so to prevent her from dodging ahead of me I just grab the other handle and keep her close, since at that point  the tree and penalty yard systems don't work.  BTW, I want to brag... there's another dog we sometimes come accross on our walks that is also very hyper, and both Scout and the other dog start going nuts tugging and jumping when they see eachother (sometimes it's refreshing to find that your dog isn't the only spazz on the block!).  Since we've been working so diligently with her walking skills, I noticed on the last run-in with this dog Scout calmed down much more quickly than usual, and actually sat without my say-so, and we were then able continue walking with no tugging.  The other dog, meanwhile, continued to tug and jump even as we walked away [sm=clapping%20hands%20smiley.gif]

Well here's the update.  My buddy, Dutch, has gotten used to the many horrible tastes I've added to the leash so that's not working too well.  I tried putting a length of chain at the end but lo and behold he likes to bite the chain and pull on it like tug o war.  So I took that off.  I don't want him to damage his teeth.  There are short periods of time when he'll do well and I reward him, then the leash goes back in the mouth, making it taste better next time since it now has dog treat on it.  And he doesn' t hold a toy or stick if we offer it while he's walking.
I was told by his first obedience trainer that he did well with the gentle leader on in puppy class.  Today we had him at the vet's getting a chip and she helped us to fit the leader on his now bigger head.  He didn't freak out like we expected so we'll give that a try.  This process may take a while but my plan is to have a dog that can walk on a leash someday!

Labs are very oral, but if you can get them to age 2, or so, they generally stop eating the back yard, and they carry the leash instead of ripping it to shreds. []  Work on the "be a tree" thing when you are using a buckle collar and leash, and when you need to go for an "exercise walk", use the Gentle Leader.  That way, he doesn't ever get to practice pulling you.  Check out www.clickersolutions.com for their articles on teaching loose leash walking.

Actually, I am using an old chewed up leash from the previous owner that now smells like buffallo wings...

 
I was wondering what leash you were using.  The old, chewed one could be part of the problem (the other being that oral fixation that Retirevers have).  A new leash might help him get the idea.  I understand not wanting to switch to an expensive one until you know for sure, tho.  Those cotton training leashes are fairly inexpensive, tho.  You might want to try one of those until you can teach him not to chew his leash.  Good luck!