The Zoo oppens at 10am daily. Ticket (Adults): 18€; they have discounts for Youth Card Users or Fnac users (12% discount), and other discounts (Lisboa Card, etc).
Metro Station: Blue Line - Jardim Zoologico.
In the entrance of the Park you can take pictures with some parrots.
You can spend there the entire day in Family. Inside the Zoo you can use the cable car (for free) and you can enjoy the nice view of the entire Zoo (~30 min ride).
All the Shows inside the Zoo are included in the ticket price.
The most amazing show is the Dolphin's Bay Show, during the Show you can buy fresh water (1€/bottle) and you can buy cuddly dolphins (between 2€ - 8€), the kids will love them! In the end of the show you can also take pictures with a real Sea Lion.
There are other shows: Sea Lions Feeding, Pelicans Feeding, Free Flying Birds and Reptile Presentation. I saw the Reptile and Flying Birds show and in the end of the show you can touch the animals and take some pictures with them. The shows are real nice and they explain you the animal life (in portuguese language, even if you don't understand Portuguese, the Shows are really nice).
They have about 5 restaurants where you can lunch. They have also a McDonalds. But if you want, they have a pic-nic area, but you have to bring some food from home. Maybe some sandwiches and drinks and enjoy the pic-nic area if you don't wanna go to the Restaurants area. Prices are very reasonable.
Hundreds of different animals! Worth the visit!