Just a quick and simple tip. If you are on ubuntu and working with WordPress on a local installation, and you are finding yourself in the situation of being unable to access your posts when you enable pretty permalinks (which is, a custom post structure in Settings > Permalinks), the reason could be that you simply need to enable mod rewrite on you local Apache server.
How to do it? Just open up your terminal and write:
sudo a2enmod rewrite
sudo service apache2 restart
Now everything should work!