I would say May rather than April as the season in most resorts starts 1st May.
I would recommend Bitez on the Bodrum Peninsula, it is a lovely resort, not too busy but plenty of places to eat and drink. It has a nice beach and is very family friendly. Just along from Bitez is Gumbet of you fancy a livelier resort for an evening and Bodrum is just 15 minutes away by bus.
We had a lovely holiday recently in Cirali, the beach was lovely (very hot though - in July!), sea was clean and clear. There are some sights such as the Chimera (some kind of natural gas fire from what I could make out), also Olympos ruins. There are hotels with pools but not big all inclusive resorts.
If you want more of a family resort near nightlife then Alanya might be a better option
We have only been abroad once before (2 years ago and made it as far as Normandy) and after a cold week shivering in a tent last week on "holiday" we have decided to be brave and venture a little further! So our local travel agent dumped a pile of brochures in my arms and after HOURS of reading we all like the look of Turkey. This is our first big, proper holiday and we want to go somewhere warm (not too hot), with a beach and sea for swimming, a pool (with a slide or 2, though that's not vital) and a few sights to see. We are a family of 4 - me, DH, DD10 and DS6. I'm thinking late April / early May......will it be warm but not hot then?! We also like to sleep at night so would prefer to be away from nightlife areas, but within walking distance of it IYSWIM?! I eagerly await any replies evenifit'stotellmei'mdreaming.