Dog jumping and biting

Question
Hi,

I recently rescured a dog from a shelter - have had her about 2 months now.  She is between 1-2 years, a shepperd mix with a look of boxer and retreaver in her.  

When we got her from the shelter, we were told that she was abandoned there - left tied to the fence for the shelter to find her the next day.  Also, looking at her when we first got her, she looked like she might have just had puppies by the way she was hanging.  I understand this must have been tramatic for her, and I think it is possiblity that this is the reason I am having some problems with her - but just don't know what else I can do to show that she is going to be okay with me.

I am taking her to beginners training classes - and she seems to be doing ok with the basic commands.  However, I do have a problem with her agression.  When I am walking her, she is trying to jump on people walking by, even when I pull her over, get her to sit and tell her no jumping.  She also gets aggressive at night and tries to attack her leash - biting at me, showing her teeth and with a scary growl - she looks like a dog pocesses.  Last night had me worried b/c she attacked me in the back yard as I told her to get away from the grill - she was eating grease.  As I stood up, she lundged at me and bit me pretty good.  I understand I should have just let her go in some part, but just getting concerned that if I am her owner and she is treating me this way - its only going to be time before she hurts a stranger.  Any suggestions on what I can do to help curb this aggressive behavior given the little bit of information I have about her background?

Thanks for any insight on this!

Answer
when walking her,use something called a 'prong' collar,and anytime she steps out of line check her back hard,and be very tough on her,this is a serious problem and you need to get on top of it-they don't usually try to fight a prong collar as it is too difficult for them to even try

Also it might help to have a water bottle with you,and when she lunges at you(like she did the other day)give her a good soaking,even use a bucket or a hose if you have to and yell as loud as you can 'no leave it' And don't stop if she is acting scared,it's a lot better to have a scared dog rather then a dead dog,which may happen if her aggression isn't stopped now

It's also good you are taking her to training,because that would be another thing I would advise,and maybe after class if you can have a few minutes to tell the trainer the problems you are having with your dog,he/she may be able to work one on one with the problems you are having with her