Biting strangers; peeing when nervous...

Question
I have a 4 1/2 yr old possible Border Collie mix.  She is mostly black with
some white on her chest, feet & mouth.  She is only about 30 lbs, so she is
definitely a mix of something else; we thought she might've been part
Cocker Spaniel when she was a puppy because she had curly hair on her
ears.  I got her in Jan. of 2004 from my sister when she was only about 2
months old; the first time I took her to the vet they said she was born
sometime in mid-Nov. 2003.  My sister had gotten her from someone else &
already had her for a few weeks before I got her, so I really feel she was
probably taken away from the mother too soon.  Anyway, we've had issues
since day one with her being aggressive, growling & biting.  She has issues
with all strangers and people she is not familiar with coming into our home
or when we are out walking, even kids.  I usually just put her in our
bedroom or in her cage when we have visitors or people in our home she
isn't familiar with for fear of her biting them.  When she has been out, she
won't necessarily "attack" them, but will try to nip at their ankles as they're
walking around.  I have two kids & she has always been fine with them &
even with my husband, even though he's never been crazy about having a
dog.  I grew up always having a dog; he didn't.  Also sometimes when she
gets nervous about someone approaching her or even petting her when she
lets them, she'll pee all over the place.  The few times I've had to board her,
the people there would never even go near her for fear she would bite them.  
She would just stay in the kennel the whole time & stink up to high heaven
by the time I would go get her.  She loves me, she loves my kids, & even
loves my Mom & my sisters.  It's like she knows my family members,
although sometimes she still has issues with some of them, like one of my
brothers.  It's almost like she picks up on certain things with people.  
Anyway, I know she has definitely been in need of some major dog training
all this time, but I always felt I couldn't afford it, plus I knew the extra
expense for the dog wouldn't make my husband happy.  Any advice on any
other things I can do myself?  I have watched the show "The Dog Whisperer"
many times & have always felt she really needed some intervention like that.  
I know that guy would have a real challenge with my dog, but that it would
be good for her too.  I have read numerous articles on dog training & dog
aggression, but I'll admit I've never followed through enough on any of it.  
By the way, when I take her to the vet for her yearly visits, I take her with
her muzzle already on as she freaks out and will growl & bark at the people
working there as well.  She also has been spayed.  Thanks for any additional
advice you can give me...

Answer
Its good that you have watched the Dog Whisperer, although highly edited, his presentation are good examples of dealing with various issues and the example dogs/solutions are the common ones most trainers employ.

If you browse some of my other answers you will find a common thread. All dogs need obedience training. All dogs will assume they are  the pack leader if the humans do not fulfill that role in their lives.

There are many opportunities for obedience training (which is pack leader training) from clubs, individuals, park services, and retail stores. The retail stores usually provide the lease value because their training is limited by company policy and lawyers afraid of being sued by a customer and the training areas are in the middle of the store with people and other distractions all around. But for $99 or so, its a start.

Dog clubs usually offer more individualized attention. In Chicago as many other areas the Park District, YMCA and animal rescue groups have or will direct you to training classes. At the very least, we have a DVD and book for $29. that explains behavior, training and demonstrates everything from the correct collars to handling nipping an other issues and all the basic obedience commands.  

All of the issues you have raised point to the dog being the pack leader and feeling it is the boss. At 4 1/2 years old, the dog has learned this position so it will take effort to bring it around to being #2 in the pack with all the humans being #1. But the breed is known for its intelligence, so with a good instructor it should get the message, it will take practice and consistency to keep the dog trained.

Immediately I would suggest the nothing for free program. The dog must do some command, sit, down, whatever, before it gets any food dish, water, treats, toys. Confiscate all the toys and make the dog perform a command to get one. At the end of the day, take the toy back. If the dog misbehaves, take the toy away. This is how the dogs learn in the wild who is pack leader. Pack leader eats first, goes through doors first, gets toys first.

Regards,
Henry Ruhwiedel
Westwind Kennels LLC