By default posts in WordPress are listed in reverse chronological order. To change the order you usually need to edit the publishing dates of your posts.
One way round this is to use the PostMash plugin. It displays all your posts in an Ajax interface and allows posts to be simply dragged and dropped into a new order.
Posts can also be changed from draft to published at the click of a button (and vice versa).
If you want a quick and easy way to organise your posts in order then I recommend checking PostMash out. If the plugin is disabled then all posts will go back to their normal reverse chronological order so you don’t have to worry about messing things up.
More information can be found at the link below :)