It's mission, among other things, is to deliver the multi-purpose logistics module Leonardo to the ISS, along with multiple science racks and equipment for use on-board the space station.
That means there are only 3 more shuttle launches scheduled, before the Shuttle program is scrapped. Sadly. The shuttles are cool and have been helping mankind do space science since the 80's, but I guess they are do for retirement, I just wish we had a real replacement ready.
I mentioned the previous launch (STS-130) in another post as it was the last night launch, but STS-131 was launched in the morning, so the sky was still dark at first.
You can see some awesome photos of the launch here (the text is in Danish, but he pictures speak for themselves). The image below (from the above link) shows the plume of smoke from the launch and the Discovery creating contrails over the Atlantic.
After the launch of Discovery (image from http://www.martin.gl)
I've just watched the docking of Discovery to the ISS, in real-time video, on NASA TV. Of course it's too late for you to do the same now, but check it out anyway, or wait until something cool is announced and then watch for that (such as this docking).