When our dog Annabel went blind, we didn't know how to help her. She was severely depressed and unable to cope, bumping into things, getting disoriented, going to the toilet inside, sleeping a lot, moping, etc.
I followed the advice in this book, and within two weeks, Annabel was able to negotiate her way around the house, find her bowl and water, get up and down the stairs and go to the toilet outside.
Within two more, I was walking with her in the park, and within another month, I could take her pretty much anywhere.
I simply added some extra commands when out walking: "up" for a little step, "ready, up" for a big step; "down" for a little step down, "drop" for a big step down; "turn" with a lead tug to indicate direction. Together with commands she already knew, "stop", "cross the road" (which means trot quickly), "OK", which means go, it gave us all the tools we needed.
We'd be out in the streets, crossing busy roads, sitting in cafes, negotiating crowds and she was fine (as long as the crowds weren't too thick). We'd also take her into the country, along beaches, bush tracks, up hills etc.
People often couldn't tell that she was blind because she looked as though she was doing everything herself. Ocassionally she'd need a little reassurance, a bit of a pat, and then off she'd go again.
The key to this was making sure that she got the command *before* she was expected to do it, so that she didn't find the drop or step before I gave her the instruction. That way she learned to trust my commands, and to relax enough so that she wasn't always worried about tripping or bumping into things.