First, you should really do a search on this board itself. There have been TONS of posts about Yasmin!
My experience:
~ I did gain weight - about 8 lbs in 6 months
~ It did clear my acne in 4 months, but I had an initial breakout in the first month.
~ My periods were much shorter and lighter
But of course, every woman's experience is different, just depending on your body's reactions to the hormones. You never really know until you go on the acutal pill yourself.