We spent a very pleasant few days in Dubrovnik a few years ago. I would caution you that there are NO sandy beaches as far as I know in Croatia, and most sea swimming is done from rocks and down ladders.
If you have young children, you might want to look for a hotel that has particularly good children's pools and activities. You could look at the following resorts for starters, Dubrovnik, Hvar, Split, Zadar, and Cavtat. I don't think there are very many Croatian hotels that do all inclusive in the same style as you might expect in Greece or Spain. B&B or HB seems to be the norm. We didn't eat out as we were only there for a few days and it got dark before dinner time in May - and it rained heavily, so sitting out wasn't an option .... think soup and hot chocolate!!!
Nice places to visit if you like history - Mostar, Cetinje and Kotor come to mind and there are plenty of islands to visit on boat trips.
Balkan Holidays and FTI have many hotels to choose from. Hope you find what you want and have a great time.