craftgrrl | Copyright and Sewing Patterns

Who can show me a decent website about sewing pattern copywrights? Knitting patterns?

See, I NEEEEED to use up scraps and I decided to make and sell little things, from purses to hats to pyjamas, etc. But I am lousy at drafting patterns and I want my stuff to be good, and I spotted good ideas in books and with patterns. But I know it's practically immoral to make and sell them exactly, so I want to be inspired (read: based off them) by these.

So who can tell me about this? I've heard that one has to change a pattern by 30%, but what constitutes a change? Would extra trims or sizing be considered a "change"?

I already checked the FAQ but those memories have more to do with images than sewing/knitting patterns.