How much inventory should a company keep on hand?

I would advise you not to hold any inventory if possible especially when it comes to running an online clothing store. This is because fashion changes very fast and you do not want to left with a lot of outdated stock in hand that you cannot sell. Plus the fact that your capital would be tied in your stock.

What you can do is to look for drop ship companies like www.Doba.com or www.Aliexpress.com and set up your online store linking to them. In the event that customers wish to purchase anything from you, you can have the order processed and the drop ship company will liase with the actual merchants to have the product shipped directly to your client.

If you need some proper web-hosted shopping cart to get some idea on how to do it, you can check out :

www.volusion.com

www.instantestore.com

They offer free trials. Hope this helps.