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 tropical stay, 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 cassowary, a large non-flying bird with a "helmet" growth on its head to protect it as it runs through the forest. Of course, as with all of far northern Australia, saltwater crocodiles are present
Tropical climate with moderate seasonal variations. The summer is the rainy season.
It's easiest to get around by car, but buses run from Cairns and Port Douglas all the way up to Cape Tribulation. Many companies offer packages of accommodation and transport to the area. Most people opt to drive to Daintree from Cairns which is about a 2 hour trip.
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.
The road is sealed all the way to Cape Tribulation and all rental companies allow cars to travel as far as the Cape. 4WDs are required only for the Bloomfield Track.
Interactive Rainforest Guided Walks with Aboriginal Guide 
Mason's Tours is the orginal tour operator at Cape Tribulation and offers 1/2 Day Walks, 2 Hour Walks, Nightwalks and 4WD Tours. Run by the Mason family, who originally came to the area in 1932, Mason's Tours is hard to beat for local knowledge.
Cooper's Creek Wilderness  runs excellent bushwalking tours. Pru (the owner) is very warm and knowledgeable. Take swimmers for the swimming hole at the end. Tony's Tropical Tours is also supposed to be quite reputable.
There are several operators running riverboats so you can spot crocodiles on the banks of the Daintree River and also Cooper Creek
At Rainforest Hideaway B&B on Camelot Close in Cape Tribulation there is an interesting sculpture trail through the rainforest.
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.
Try some native Australian cuisine at Julaymba Restaurant & Grill. Rainforest salad is great, with native ingredients 
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.
Coconut Beach Resort at Cape Tribulation has been renamed to Cape Tribulation Resort but is currently closed awaiting new owners.
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.