ok i just got my new kindle 3.. ive had the kindle 1 until it died.. so im making categories on it..my question is when i put the books into the category do i delete the book off my list since its under the category?

I'll answer this here for other people, even though I already answered you in chat. lol

Do not delete the books after you put them in collections. The reason you are still seeing all the books on the main screen is because you haven't changed the sort. Change the sort (at the top of the screen) to Collections and you will only see collections and books not in collections. To change the sort, click the up arrow key to underline the top line where is says "by...." on the right. Then click the right arrow and choose sort by collections.

lol thanks Pat :P im glad to know im not looking at duplicates anymore haha