Hi Melissa... I have a lot of experience with having products made to my specifications in China and Taiwan. (actually all over the world but I'll focus on these two)
First... Yes you can forget about IP pretty much... but on the other hand remember that they sort of don't care. Everyone thinks their design/idea/method is the best and fear it being stolen, even myself. The plain truth about that is that you need more than your idea, you need a passion for it and your audience... and until it's a big brand you likely don't have much to worry about with others doing the manufacturing.
Next - After you spend time researching and negotiating with a few potential partners to manufacture your goods, you need to get over there and meet the folks and see their facilities. Reason for this is that many 'agencies' in china will claim to be manufacturers, but they don't manufacture anything at all. They are a small office with an internet connection, and represent themselves as makers all kinds of things they buy as distributors.
An excellent source to begin that research is alibaba however that's not the end all for sure. That site is full of those 'agencies' you will recognize by seeing 20 'manufacturers' with pictures of the exact same product. You need to find out which one is the true manufacturer.
Finding the true source of the material and labor and infrastructure is key here. Using anyone else will have a big effect on quality, lead times, and mutual understanding.
Another big thing is that usually if you receive something that is not up to standard, you're stuck with it, whether you think it's their fault or yours. Being a startup you're not going to have the long term history to justify any free replacement orders if there is errors... another reason to visit with some samples of your own, and view things there.
Best of luck to you. For the record I had my product line 'Cobra Controls Corporation' security products made over there, so I don't have clothing experience... but these are general guidelines I would give anyone.