Having done this holiday i can tell you ATM's are hard to find and it is best to take sterling (or euros if you have any) and maybe card as back up. Most of the hotels will change money for you in very small amounts so we found it best to change as we went.
Dont take American dollars as they put a 10% surcharge on for exchanging them.
On a good note things such as drinks and food are reasonably priced so found it a very cheap holiday when it came to spending.
As Monty has said its mainly half board plus there is 4 all inclusive nights which really helped keep costs down. In fact at the two resorts we arrived early and left in afternoon so gained a couple of lunches, 3 instead of 2 during a two night stay. :thumbup: