Bilingual Dictionary:
Collins Spanish-English dictionary
Spanish Dictionary:
Diccionario de la Real Academia Española
Language Corpora:
These are great sites for looking up samples of authentic Spanish. It is probably the closest you are going to get to natural Spanish without talking directly to a native or going to a Spanish radio station or television. It is especially helpful for finding grammar examples that you might be struggling with.
Sitios dedicados al estudio y aprendizaje del español:
- www.studyspanish.com (This site provides access to various hands-on vocabulary and grammar exercises)
- www.spanishlanguagehelp.com (This page provides the user with various activities for practicing Spanish)
- www.conjuguemos.com (This page provides verb conjugation practice)