Club Las Rocas is situated about 5 miles out of Puerto Plata just off the PoP - Santiago main road. It is inbetween Costamber & Cofresi up a dirt track of about 400 yards!
If you are looking for night life by going to Puerto Plata, this may be a little inconvenient for you (local taxis & motoconchos don't regularly go up there) but the lady who runs it might be able to organise some form of transportation for you.
Depends on what you are looking for & for how long - Puerto Plata Beach Resort has rooms/appartments to rent out (US $28 per night but COULD be less for a month or two) & ApartHotel Lomar has nice rooms too at US $25 per night. - Grahame.