Argh! Fucking laptop! My post got deleted just as I finished it... And I was so proud of what I had written too.
I'll try to write it all up again, but I might not put much effort into it.
You have been notified.
Doubtless this has already been said, but doesn't having a set book for moral codes to follow sort of defeat one of the main purposes of being an atheist?
That's not to say that an Atheist can't, if he or she so chooses, decide to use a book or the words of someone to influence their decisions on morality. But you need to keep in mind that Atheists aren't an organisation or a religion. Atheism is simply the decision to reject the idea of religion, it is the decision of an individual, that person doesn't have to follow any other rules in order to be an atheist. Individual atheists can easily have no viewpoints in common aside from the whole religion thing. One atheist could be a kind hearted Samaritan working in a homeless shelter where they hold the position of "chief dispenser of hugs", while another atheist could (quite ironically) be a fanatical douchebag intent on spreading the knowledge of the "Master belief" to others though whatever means necessary. One atheist could be an environmentalist, while the other could be a working on a Japanese Whaling ship.
Having one tome to encompass the views of all atheists, from all walks of life and moral standings, will quite simply not work.
Besides, we do have moral codes, due to humans being rather more on the theist side of things historically, they happen to have been put into the bible.
While I don't think all of the ten commandments are really necessary (particularly the ones specific to worshiping god), the key things like (to simplify a bit) "Don't y'all kill a fool", "Stealin' is wrong" and "Don't be a dick to your neighbour and be all up in his space by doing stuff with his woman" are still relevant. Having a book just to place down what is accepted as common human decency to most people seems like a waste of time.
If an atheist really needs to suckle at the warm inviting teat of a book for moral guidance, might I suggest that they go back to being religious? As they clearly aren't cut out for this whole "Think for yourself" thing.