About sizing for sweaters

I know that when you are sewing a sweater you are supposed to use the size based on your high bust measurements, and then make adjustments for your full bust. Is this the same with knitting and crocheting sweaters?

I found this pattern http://www.coatsandclark.com/Crafts/Knitting/Projects/Apparel/LM0259+Knit+Lace+Border+Top.htm
and I think it might be a good first sweater project for me, but I am afraid that it will either be too big all around, or it will be too tight around the bust for me to ever feel comfortable with. I don’t really understand the sizing. It has a range of sizes for xs, s, m, l, xl, and then it has sizes for busts. How do you find the right size?

Your best bet is to measure a sweater that you have and like the fit of and match that to the finished sweater size of the pattern.

on your instructions a small fits a 30-32 inch bust, but the sweater is 34 inches around. This seems to be a lacy knit, so the fabric will be quite stretchy, the fitting should not be that crucial. Maybe it’s my monitor, but I sure can’t tell what the sweater looks like with that dark yarn.

I think I understand now, it means that the sweater has a 2" ease in the bust area. If I decide to make a larger size to give me a little more ease, will it affect how it fits on the shoulders?