Advance planning for Next Summer



Hey everyone, seems that there is a lot of info on this board. I am a 23 year old female, working as a bartender at a club on South Beach. I would like to make plans to spend next summer working over in Ibiza, thinking form May till August. I speak fluent Spanish, perfect English. I have never been out of the country though, and have no clue as far as what to expect. Is there anything that I can do in advance, such as the residencia, etc? Do all clubs/bars give work permits/contracts? Here, its basically a cash job with no strings attached. What about taxes, will I have to pay any there, or here in the US?

Any info will be appreciated.