Except for the ñ, most people will leave out the accents like é ó á and í when searching in Spanish. It is just too much of a hassle to type it in on the Spanish keyboard. There is a unique key for ñ but on the other accents you have to type ´ then the corresponding letter.
Check out some keyword lists and message boards, for example, and you will see that most people type without the accents unless it is needed formally or there is a clear distinction where certain words need the accents. In most cases, however, people will know the distinction in relation to the phrase or sentence that is being used.
Now, that isn't to say that people will not type the accents, therefore it should be on the page translations, but you should also target keywords without it as well.