Look into a guy named Stephen Key. He has written two books, and the first one One Simple Idea talks in the first couple chapters somewhere about how he got started in soft goods. I would be able to give you a more specific answer but the book is in WI and I am working in PA this week!
There is some good advice on a post on a different forum I found a while ago. I had to dig around to to find it but the link is Designing a clothing range and getting it manufactured Check it out, I hope that helps. Do you have a website with any sneak previews?