Closet space in the average home is usually quite limited. It is also a space that is least utilized. Rebuilding a closet or two is a good way to also reorganize the clothes and clean out things that are unused, outdated or won't fit.
If this is a DIY project, probably the best way to go is to purchase wire shelving with the appropriate track. Easy Closet has an online designer the DIY'er can utilize with some standard designs at www.EasyClosets.com.
Empty the closet of pole and shelf and measure the space and draw a picture of what you want before staring. Use a level and a stud finder so that your work has good results. I would also advise that you search the net for pics of professional closet designs. You may find some good spacial concept that suits your needs and makes plan more practical.