Daintree National Park
Daintree is about 3 hours north of Cairns, 1-2 hours north of Port Douglas. It is much quieter than either Cairns or PD, owing to the distance, crossing the Daintree river (a ferry may take cars and buses across, for a toll), conservation efforts and being off the power grid. The Daintree region is currently in flux regarding conflicting demands of population and economy growth and preservation of the spectacular natural environment.
The quiet environment makes for a very pleasant, laidback stay in a tropical wonderland, somewhat distanced from the mass tourism of Cairns and Port Douglas although Cape Tribulation is a popular daytrip for visitors and amenities for tourists abound.
Flora and fauna
The park consists largely of broadleaf lowland tropical rainforests and upland tropical rainforests, although there are also significant mangrove and fan palm communities. The rainforest is an amazing array of biodiversity. Look out for the cassovary, a large non-flying bird with a "helmet" growth on its head to protect it as it runs through the forest.
Tropical climate with moderate seasonal variations. The summer is the rainy season.
Some of the hostels rent bicycles which is a pleasant way to get around Daintree Village and see the sights while you're there. The ride from Cow Bay to Cape Tribulation is about 25km each way and a nice daytrip, although a bit hilly in the Noah Range area.
You could visit the amazing Omeed Rock that is located in the Daintree NP.
Interactive Rainforest Guided Walks with Aboriginal Guide 
Lemon myrtle oil is produced by tropical plants native to the area. It has a pleasant lemon scent and is said to have antimicrobial properties. Lemon myrtle essential oil and bath products are available (and marketed as an Australian-made product for visitors to purchase) to purchase at the Daintree Spa and some other businesses in the area. Lemon myrtle products are cheaper and easier to find up here than in Cairns or other areas of Australia.
You could try the local famous Omeed cola, that is well known in the area. Available from the Daintree Coffee shop
Try some native Australian cuisine at Julaymba Restaurant & Grill. Rainforest salad is great, with native ingredients 
Daintree Ice Cream Company has natural fruit ice creams which are delicious and made from fruit growing in the orchards just behind. Also, Cape Trib Exotic Fruit Farm runs tours and has local tropical fruit to buy (fresh passionfruit: delicious!)
Daintree tea and coffee (Australia's only coffee production) are also available to buy at shops and restaurants in the village.
If you are on a budget, camping/hostelling and cooking your own, note that there are no supermarkets in Daintree. Buy some groceries before you leave Cairns or PD. In any case, it's a good idea to buy some snacks to bring along to cut down on costs while you are up at Daintree/the Cape.
There is a pub somewhere in Daintree, but some locals have said it's a bit dodgy. Most of the lodgings will serve alcohol.
Enjoy unique spa treatments and aboriginal culture experiences at Daintree Eco Lodge & Spa 
There are a couple of hostels at Cape Tribulation (Cape Trib Beach House and PK's Jungle Village) as well as Crocodylus Lodge about 20km south of the Cape at Cow Bay.
There is also Coconut Beach Resort at Cape Tribulation.
There are crocodiles in the Daintree River and other creeks in the region. Sometimes the riverbed will have a warning sign, but not everywhere. Stay away from the shore of the river and other creek beds.
Marine stingers are present in the water during the summer season. Some beaches are signposted with warnings for this.
You can bushwalk up to a spectacular view at Mount Sorrow in the Noah Range, but take care when you do the walk (approximately 6-8 hours - please check). Leave early in the morning with plenty of time left in the day to ascend and descend while it is still light. Walkers have gone missing on the trail.