Word Reference is the dictionary that I used to get through my Spanish program. It offers not only the definition of the language but most words also have the audio icon so you hear the pronunciation of the word. Especially helpful is the discussion forum of the word with native speakers from around the Spanish speaking world confirming usage of the word in various contexts. http://www.wordreference.com/
Linguee is a new discovery of mine and I love it! It is a dictionary too, but much more. It is a corpus based dictionary. A corpus is a searchable compilation of thousands of documents in the target language. This gives you the ability to test out how combinations of words are used by native speakers and see how phrases translate. You can look up a phrase structure in Spanish to see if those words word together to correctly form a phrase. If you are not sure how it would translate, you can see them side by side in both languages. Really cool also are the applications available. You can use a plug in that allows you to right click on any word on your computer and look it up in the dictionary or put in a dashboard widget to always have the Linguee dictionary available. http://www.linguee.com/english-spanish
Wow! This one is cool. For those of you who are super concerned about your pronunciation, this is a web site put up by the University of Iowa on Spanish phonetics. You can see the entire phonology of Spanish, watch the mouth of native speakers say sounds and hear them work in a variety of words, and see the animated video of what's going on in your mouth to produce the sound. http://www.uiowa.edu/~acadtech/phonetics/#
Yabla and LoMás TV is one of my favorites for listening comprehension practice. I will be using lots of their videos in class. It is a subscription based site but you can access some for free trial. The subtitles are at the bottom of the videos and you can click on words for definitions and replay when needed.
http://spanish.yabla.com/
http://spanish.yabla.com/
A great app to have on your phone for subway rides. Vocabulary games until you memorize it! https://itunes.apple.com/us/app/bidbox-vocabulary-trainer/id353571574?mt=8