After selling our restaurant (land, building and business) my advice is that you let no one look at the books until they can prove they have the ability to buy. Too many prospective "buyers" show up full of grand schemes.
I will disagree with food pump on people's reactions if the sale is announced.
When we decided to go public with our intent to sell, the local paper ran a brief article in their food section because we wanted to get the word out. Previous efforts with real estate people went nowhere for years. They claimed to have listed the business but we never got any responses.
Once it was announced in the paper, more than a few people showed up with great plans but no money. No purveyors ever called to change our accounts or ask for any change in payments. This may have been the result of 23 years of paying our bills in full but perhaps not.
Business wasn't affected in the least. People continued to come as they always had. There were occasional inquiries from long time customers about the status of a potential sale but more for conversations sake.
None of our long term staff left and we continued to hire new part time employees with the full disclosure that the place was for sale. Every member of the staff had a new job before leaving but all stayed until the last day.
We showed the books to one or two people before realizing they were simply fantasizing and did not have the resources. We stated in the initial announcement quite plainly that we would not hold any paper. Several people tried to ignore that.
We finally sold at the price we wanted without a broker. Just a lawyer. Once the sale had gone through and it was announced that we would be open for one more week, the place was a mad house every day with people coming in for just one more meal.
So your experience may differ but if you have a steady, established business, I don't see why announcing you want to sell would be a bad thing. It certainly worked well for us.