Now for the most important information in the guide - where are there bathrooms open to the public?
The casinos are always the best place to use the restrooms. They tend to be both clean, and stocked with toilet paper
There are many public bathrooms in Macau. They are fairly clean, but I have never seen any that had toilet paper, so you might want to bring some of your own if you will be out and about away from the casinos.
Most are labeled in English, but occasionally you may find some that are only in Chinese. With a little imagination, one of the characters at the start of the label looks like someone starting to sit down ... this is the women's bathroom.
I'll improve on this list in the future, but for now here is a short, partial list
Near the Grand Lisboa on Rua de Santa Clara there is a small park named the S. Francisco Garden. Coming from the Rua de Santa Clara entrance you can see flowers arranged to write the current year. This is also the oldest garden in Macau, but we can talk about that after you find the bathrooms about half way up the hill.
Senado Square, Largo de Senado, or San Ma Lo. From the fountain in the center of the square, put your back to the fountain and face the ruins of St. Paul's (have your back to the busy street nearby). Walk a short ways and turn left on Rua Norte do Mercado de S. Domingos. Dodge the vendors, cross a small street and go into the big market building - Mecado do S. Domingos. Walk past all the stalls to the elevators in the back. Go up to the second floor (or was it the third) and the bathrooms are to the left when you get off the elevator. If I am wrong about the second floor, try the same location on the third (or fourth). I wasn't paying that close of attention so I might be wrong about the second floor, but I do remember it wasn't on the bottom floor. I'll have to ask my wife.
A-Ma Temple. There is one in front of the A-Ma Temple, close to the Maritime Museum
Taipa Pequena trail. They have a nice trail that goes around Taipa Pequena. The restrooms are close to the 2.0 mark, when you are facing the Macau peninsula.
Estrada da Baia de Nossa Senhora da Esperanca. This is the divided street between the Galaxy and the residential area of Taipa. It is a short walk from the large rock at the Vila da Taipa square. Face the rock with your back to the Galaxy. The restrooms are about two blocks to your left, in front of the hospital. They are between the parallel roads Rua do Pai Kok and Estrada da Baia de Nossa Senhora da Esperanca.
Taipa Houses. There are two sets of restrooms here. One is behind the Taipa Houses, close to the stairway that takes you up to the Our Lady of Carmel Church. It is under the Rua da Restauracao.
The second set of restrooms near the Taipa Houses are to the side of the Carmel Garden, behind the administrative building that faces the church. From the Our Lady of Carmel Church, walk down the street to the Carmel Garden. When you pass the administrative building, turn left into the garden, and go straight towards Taipa Village. The restrooms are a little hard to find, but are down the walkway to the old Taipa Village.
Historic Taipa Village
On either end of the Rua do Cunha, there are public restrooms. One is in the square with the pavillion, that is closest to the Taipa Houses.
The other is at the other end where the street opens up in a plaza (Cozinha Pinocchio is here). Leaving the area with all the shops on Rua do Cunha, the restrooms are to the left.
Templo da Tam Sin Sing (Tam Kung Temple). When facing the temple, the restrooms are to the right, by the edge of the water.
Along the river, where the Avenida de Cinco de Outubro, Rua dos Navegantes, and Largo do Matadouro meet, there is a small roundabout in the middle of the street. The restrooms are in the building on that roundabout.
Largo do Presidente Antonio Ramalho Eanes. At the square/park in Coloane Village (if you took a bus, this may be where you got off) across from the Lord Stow's Bakery. There are two restrooms near here. One is a short ways down Estrada do Cheoc Van. From the park, walk about 20 meters down this street and the restrooms are on the left.
The second set of restrooms near this park are in the small market across from the park. Walk in from the park, and they are of to your right in the back corner.
Templo de Tin Hua. If you are taking the self guided walking tour, I remember there is one more set of restrooms between the Chapel of St Francis Xavier (the main square) and Tam Sin Sing Temple. I think it was close to the Tin Hua Temple