Hi, don't think there is anything you really need to know or take with you on your trip. There are several supermarkets which stock everything you might need including things like mosquito repellents, suncream, travel adapters and stuff like that so if you forget to bring something you don't need to panic. The reps have told us in previous years that although the water is technically drinkable, it is more advised to buy bottled water from the shops which is very cheap anyway. The closest ATM is in Sidari, a 15 minute drive away but there are several places that exchange travellers cheques in Arillas for a small fee. We usually use the Marina Hotel on the beach front for that and they also have safety deposit boxes for hire. We normally bring travellers cheques because they only charge commision of about 2 euros for a 100 euro traveller cheque so you don't lose much in commission. Also most of the supermarkets takes cards such as visa so you shouldn't be stuck. I don't believe there will be any sharks in the water, or at least I have never seen or heard of any seen near Arillas so you should be alright in that respect. Hope you have a nice time, anything else you want to know, just reply to this posting.