Quite a few teachers have been asking me about how to use voicethread because they see the real potential that digital storytelling of this nature can have on the classroom and on learning. A few, however, have been delayed in trying it because of technical difficulties. Although there a much better tutorials out there on Voicethread (like this one), I would like to add my few screenshots to the mix in order to give some options. (In case you were wondering, I used Skitch in order to create these screenshots, please e-mail me for an invite to this extremely useful software.)
The following tutorial (of sorts) only goes over uploading images and recording your voice. Check out the above links for more info.