If you are a visual learner, or if you’d just like to expand your vocabulary, you will undoubtedly be interested in Pons’ huge online German picture dictionary (http://www.bildwoerterbuch.com).
The dictionary contains 6000 words in 17 different categories and with images for all of them. You can browse by category (e.g. Earth, Clothing, Plants, Animals, Sports, Science, House) or you can search for a word, or part of a word, in either English or German. If you are browsing, you typically will click through a few layers of images, the topmost layers containing the most general words and the final layer containing the most detailed images. For instance, clicking through the pages Transport und Fahrzeuge > Strassenverkehr > Auto will bring you to this image (which is one of several on the page under the category Auto):
If you click on one of the images, then you get an image that contains more specific vocabulary. For instance, clicking on Karosserie on the page pictured above yields the following:
Below each image is a list of the included vocabulary with German and the corresponding English words and with links to audio pronunciation for both languages. Be aware, however, that the intonation is not always correct for the German words. For the words I tested, the speaker uses rising intonation at the end of every word, as one might do when reading a list of words in anticipation of the next word.
Given the level of detail this dictionary offers, it is best suited to advanced learners and/or learners who need to know very specific words in a particular field. It also contains only nouns, no other parts of speech. Still, with 6000 words there is sure to be something here for everyone.