You'll have a great time i'm sure! August is VERY hot but Trianda is on the west coast so there's always a cooling breeze. Do explore the inland side of the traffic lights in Trianda - it feels more lived in than the tourist areas and (if it's still there) there was a fabulous 'no frills' taverna just across from the Spa supermarket. Take a taxi from here up the hill to Filerimos - it's one of the most beautiful spots on the island.
There's a regular bus service and a taxi into Rhodes Town will only cost around a fiver. The neighbouring resort/village Kremasti is worth a visit (again v easy by bus/taxi) to watch the old greek gents playing backgammon outside the library, visit the largest church on the island and try some great homemade ice-cream at Mikes Cafe.
There's a good car hire company next to the Solemar hotel in the neighbouring resort of Ixia (can't remember the name), good prices and decent cars. If you do hire a car places not to miss are Filerimos, Ancient Kamiros, Valley of the Butterflies, Monolithos, Emery winery at Embona, Prassonissi (the southernmost tip of the island), Lindos, Seven Springs, Tsambika Beach/Monastery and Kalithea Spa.

Thanks for thie info. i visited Rhodes in 1997, but i am sure some things have changed, nice to hear familiar spots being mentioned. will try to re visit these, last time we were young and had a motorbike, could reach those hidden places easily, this time kids and grandparents in tow, a little different!!!