Both Word and Google Docs word processing have built-in document language settings that you can change to Spanish. For Word, "review" tab --> "language"; for Google Docs, "file" --> "language" --> "Espanol". This will provide an auto-correct function for any words lacking accents. However, since some words only have accents part of the time, and we want students to be proactive in adding accents, we still need another solution. This language setting bit is helpful regardless.

1. Accents in Microsoft Word

a. In the Windows version of Microsoft Word, accents are actually not difficult anymore:
"Control + Quotation Mark (" key), then vowel" creates the standard vowel accent mark in Spanish, as with the letter "o" in "La nación." 
"Control + Shift + tilde (~ key), then n" creates the accent mark used in the letter enye, as with the "n" in "Jalapeño."
Etc.

http://webster.commnet.edu/dl/dl-help/Keys-Spanish.htm

b. The Mac version of Word can take advantage of even simpler shortcuts:
"Option + Vowel, then Vowel" creates the vowel accent mark.
"Option + "n", then "n" creates the enye.
Etc.

http://spanish.about.com/od/writtenspanish/a/diacritical_mac.htm

2. Accents in Google Docs

a. One method is to install the international keyboard, which can be done via Control Panel --> Clock, Language and Region --> Change keyboards or other input methods -->

[[text]]

[[text]]

[[text]]

[[text]]