In my “Introduction to Landscape Photography” written tutorial I mentioned that I would have a future tutorial on exposure blending, and this evening I was able to put together a video that is a quick crash course introduction to blending exposures in Photoshop. This covers a basic blend using a layer mask, and an advanced blend using a layer mask with luminosity selections. If layer masking and luminosity masks are new topics for you then you should Google around for some tutorials on those subjects, fully grasping them will make it much easier to do blending.
You can see the video here: http://www.youtube.com/watch?v=7k5bRHegiXA
The original written tutorial is here: http://blog.awoodworth.wpengine.com/2013/09/introduction-to-milky-way-landscape_2.html
The 720p version of the video should be available but you may have to reload the video to get that option. Click on the gear icon in the bottom right part of the video player to find the 720p setting.
I hope to eventually put together a more extensive video that covers a start-to-finish project, starting with preparing the images in Lightroom, blending in Photoshop, and polishing the image in both Lightroom and Photoshop.