[IxDA Discuss] Label alignment left or right?

[Dye, Sylvania]

As has been pointed out, consistency is important. Especially in a desktop application, mixing alignment typically gives an unprofessional result, and is discouraged.
 
Which OS(es) are you targeting?
On Windows, the general guideline is to left-align labels; on Mac, labels should be right-aligned. These are guidelines, of course, and not hard-set rules, but software tends to look more polished when it follows the visual styles of the OS on which it runs.
 
If the software is being developed in English, remember to make field labels around 1.5x the length of the English text if you'll be localising into other lanuages.
 
As was mentioned by Jon, the labels can also be placed above the fields, but when done a lot in a UI, this will also give an unpolished result. Generally, a label should be placed above its field only when the label text is long, and with all other design considerations kept in mind.
 
For more on control layout for desktop apps, you may want to check out the Apple User Experience guides here: http://developer.apple.com/ue/ and the MS guides here: http://msdn2.microsoft.com/en-us/library/aa511258.aspx
 
Cheers,
Sylvania