Maybe you could sort amongst yourselves who would be responsible for what sections? Allot portions of the book or story out, and perhaps give little goals, like 'lets see if we can write the first chapter in a month's time'. That way, time won't run away from you. Then you could also send the different portions between each other for editing and reading. Things like Google Hangouts, Skype and Oovoo meetings would be great as well.
You can also use the application DropBox, which was made for collab projects among people who are not necessarily able to see each other in real life frequently. It's free, and very easy to use. I used it on a collab project last year, and it was great.