I recently discovered CocoRosie are going on Tour and have since become addicted to their candy-coated playland of a website. I go to Resident Advisor for their ample stash of electronic music news, mixes, and charts.
And after a long hiatus I have reconnected to Slashdot for all of that nerdy stuff that is oh-so-useful to know.
A lot of my friends have been using Soundcloud to host their mixes and tracks. The user-friendly graphic styling of the interface is alluring and streams oh-so-smooth.