Karen, I am so sorry about your mom. I have a sister in law that lost her kidneys to diabetes. She lived on dialysis for over three years until my niece turned 18 and was able to donate one of her kidneys to her mother. It was a hard 3 years for my SIL but she is doing well now.
DogAware.com Health: Kidney Disease in Dogs
The link above is a good place to start to educate yourself about canine kidney disease. The information is pretty accurate and up to date. You are right, in that without basic knowledge it is pretty difficult to ask the right questions when you are discussing Bentley's situation with your vet.
There is a lot of bogus info on the internet so you have to be careful to question everything you read, but there is good info out there too. Feel free to send me a PM if you'd like a few more good resources, and I would be happy to send them to you.
Sending good thoughts for little Bentley. I hope he is feeling well.
Diana