I need help uploading my writing!

Although I am not a total novice when it comes to computers, I am having a hard time uploading my stories form Microsoft works word processor to wrtiting.com. All paragraph breaks get lost. When I try to fix them directly from this site, one push of my space bar sends sentances sailing to unwanted places, and pressing the tab button sends my cursor down the webpage instead of staying within the story box. Pushing the backspace key is a total nightmare as well. I see other stories with perfect formatting, witch frustrates me even more. Is Microsoft works word processor the wrong thing to be using? If so what should I be using instead? Is cutting and pasting the wrong way to go? Any help would be greatly appreciated, Grant