1) what is the best way to access internet while in spain? It has been suggested that i buy a dongle locally. Would that suffice?
2) Do i need an adaptor of some sort?
Well, where are you planning to go in Spain? Will Wi-Fi be available, e.g. in your hotel(s) and/or Wi-Fi hotspots? That would be your least expensive option but might not be possible there depending on travel plans?
The next choice would be to use a cellular plan, e.g. if you are bringing a phone, does you service offer setting up the device as a 'Wi-Fi hotspot'? Of course, depending on how much you use the internet, the expense could be exorbitant!
Another consideration would be
MiFi - these are basically small wireless routers that setup a personal Wi-Fi network - plans are numerous in the USA and variable in price (pay 'as you go' might be a choice)? Not sure what is available in Spain?
Well just a few thoughts - good luck and hopefully others will provide more solutions - Dave