1000 Most Common Spanish Words
This is just one page, they have many more than just 1000 Spanish words. Translation and audio accompany each word. Very easy to access.

Lingro Dictionary
An easy to use dictionary that offers alternate word combinations based on your root word.

DiccionarioWeb.org
Online Spanish dictionary with English to Spanish or Spanish to English, just make sure you select the correct option.

SpanishDict.com
Now a meta Spanish dictionary plus community. This site is now becoming one of my favorites.

WebworkBooks Spanish Dictionary
A good Spanish dictionary with large database and common examples of how the words can be used.

Google Translation / Dictionary
Google dictionary. Easy to use and has supporting phrases.