AHello i looking for recipe for perfect buttercream. I use to do one, but is too sweet. I need something less sweet but still fine to decorating.

http://fromscratchsf.wordpress.com/2011/03/08/tutorial-swiss-meringue-buttercream/

I use 25% less butter than she does, but it's awesome.  Read through her tutorial for a great explanation of how to make SMBC if you've never made it before.