National Parks produce some pamphlets with info on some of the walks.
I can personally recommend
* Bartle Frere [a very long day walk - probably better as an overnight or through walk if you can arrange transport]
* Walshes pyramid day walk
* Kahlpahlim day walk [Lamb Range]
Lots of waterfalls to visit. [Nandroya, Wallaman, Emerald Creek, Davies Creek, etc]
I have not done any overnighters or long walks in the Daintree, but attached is an article on Thornton Peak.
I would take a lot of care up there as humidity and heat are high and sapping.
The lawyer vine is a nuisance and the stinging tree is to be avoided at all costs.
Even the extended walk down along the Herbert River on the Great Walk [make sure you look at Blencoe Falls - 4WD recommended] requires care re Saltwater crocodiles.