I found a useful document from NASA which is a good supplement to the excellent soldering workshop that Brad KM2C conducted a few months ago.
The PDF document is titled “NASA Hand Soldering Training to NHB 5300.4 (3A-2). The document is very long and has very little text in it.
Its real value in the the many high-quality images of good and bad soldering. With these pictures at hand, you will know what to look for on your next soldering project.
You can get the document from http://www.sal.wisc.edu/docs/Soldering%20Basics.pdf
Happy soldering and remember to use a fume extractor.