I have never stayed in Olu Deniz so I can't help there but I can give you some tips for Turkey:
Weather - June shold be lovely weather, hot in the days, warm in the evenings. Take plenty of sun cream with you as it can be expensive out there and drink lots of bottled water.
Food - I take it you are eating out rather than at the hotel? Turkish food is lovely, lots of different kebabs, salads, fish, Turkish pizza (pide), soup and of course all those lovely sweet desserts. If you facny trying Turkish food look out for the restaurants where the locals eat and you will not only get the best food but it will also be cheap.
Drink - Local drinks are usualy quite cheep, the local beer is Efes and is very nice, local spirits are gin, vodka etc plus the famous raki, an aniseed drink, which is rather strong if you aren't used to it. Wine is quite expensive, especially in restaurants. Any imported drinks, spirits, beers etc are very expensive so be careful about ordering a bacardi and coke or Mailbu or something like that.
Shopping - Turkey is great for shopping but be prepared to haggle to get a good price, once you have got used to the idea it is quite fun.
Turkish People - I find the Turks very friendly, they will chat to you all the time, trying to get you int their restaurant, bar or shop. If you aren't interested just say "no thank you". they will a slo chat to you all the time generally so I'm sure you will make some new friends there.
Mozzies - If you are prone to being bitten try Johnsons Off, you can get it from the supermarkets and pharmaices and i find it works better than anything we get here.
Transport - The best way to get around is by dolmus, they are little minbuses that run very frequently and you just stop them when you see them. You can also get taxis easily everywhere
I can't think of anything else but if you want to know anything els ejust ask, I lived in turkey for a few years so I may be able to help.
Hope you have a great trip, I'm sure you will love Turkey
Kedi