One of our neighbors' dogs has suddendly developed blindness, so I've been searching the 'net for applicable resources and tips. Pictured above is a home-made dog collar that incorporates cable ties to provide the equivalent of a cat's whiskers.
I found this item at Blind Dogs.net, which has a variety of other resources for owners of blind dogs, including a long list of tips to help both dogs and owners cope with the impairment.
5) Sew 1 or 2 "jingle bells" onto an elastic pony tail band (used for hair) to slip onto your own ankle, or attach bell to shoe laces, so your blind dog can hear where you are walking.Dozens more tips at the link. If you have experience in this regard and would like to offer helpful tips (or good links), to other owners, please feel free to leave comments.
12) Get down on the floor and crawl around at the dog's eye level to find anything that might be dangerous. Do the same in your yard... look for low growing branches etc. that could poke the eyes & trim.
16) Remember to speak to your dog when you are approaching to touch (especially while sleeping) to prevent startling him/her.
19) Use a short lead to avoid tripping over the leash. Not usually needed, but you can thread the dog's leash through a few feet of PVC pipe to make rigid leash for "directing" in a specific direction.
20) Sharp corners on coffee tables, furniture legs etc. can be padded with bubble wrap, fabric batting, or foam pipe insulation from the hardware store.
22) Scent important areas....doorway/doggie door to go outside (vanilla extract, citrus, pine or furniture polish) place "scent" down low on the door or molding for best "sniffing". Scent any "danger" areas.
30) Carpet sample squares are "cheap" and while your dog is learning the layout of the house put carpet squares in the doorways going into each room to make it easier to find the door openings.
Addendum: Reposted from 2012 to add this video showing that more sophisticated "haloes" for blind dogs are now commercially available: