I may be stating the obvious to some, but not a lot of people know that there are keyboard shortcuts for the accents over letters. I am talking from the perspective of a mac user, so it may be different on PC, but the default shortcut for an accent is to hold the 'option' or 'alt' key and then the 'e' key. This brings up a little hovering acute accent, and then the next letter you type will be accented- é, á, í, ó, ú.
This also works for the double dotted ü found in Pingüino for example. This time instead of option-e, we use option-u to bring up the umlaut.
Happily the tilde above ñ is conveniently mapped to option+n. It doesn't end there though.. ¡We can also make upside down exclamation marks! This is very simply option+1. ¿But what about upside down question marks? Well that's option+shift+?
(If you're also learning German, then you may find option+s quite useful)
¡Espero que os ayude!
Alt+129 = ü Alt+130 = é Alt+160 = á Alt+161 = í Alt+162 = ó Alt+163 = ú Alt+168 = ¿
Beware of ASCII codes involving Numpad 4 without Numlock on, for that will take your browser back a page as it did for me when I started writing this O_o.