You can also try browsing and posting on our forum (registration required).
Please contact us if you have any questions about the dataset and how to use it. We also have a set of suggested tasks, including snippets of code to get you started.
While waiting for the download, take a look at the FAQ, which includes a list of all the fields in the database. We also provide a subset of 10,000 songs (1%, 1.8 GB compressed) for a quick taste. To start your own experiments, you can download the entire dataset (280 GB). To get a sense of the dataset, you can look at this description of one of the million songs. The Million Song Dataset started as a collaborative project between The Echo Nest and LabROSA.