Go with proftpd, this will set up a server with access to "/home/shareftp" and give only a user access to a user called "ftpuser"

This is the process I used on a couple Ubuntu Servers to Get Running Fast

1. Install proftpd in standallon mode
   sudo apt-get install proftpd
2. Next edit the shells file and add one line of code
   1. However /usr/bin/false needs to be added to /etc/shells to make it a valid login shell. Without this when you try to ftp as a user that has a shell of /usr/bin/false you’ll get a “530 Login incorrect. Login failed.” regardless of whether you get the password right or not.
   sudo nano /etc/shells
   # add line "/bin/false"
3. Add a User
   sudo useradd ftpuser -p userftp_password -d /home/shareftp -s /bin/false
4. Set User Password
   sudo passwd ftpuser
   1. You will be asked to enter the password twice
   userftp_password
5. Edit proftpd.conf  
   1. sudo nano /etc/proftpd/proftpd.conf
   2. Adjust "ServerName"
   3. Add "UseReverseDNS off" I have it after "ShowSymlinks"
   4. Adjust "DefaultRoot        /home/shareftp"
   5. Adjust "RequireValideShell     off"
   6. Adjust "PassivePorts  55555 55655"
   7. I used all other default values I will upload a sample file to this article.
6. Edit File access rights
   cd /home/shareftp
   sudo find . -type d -exec chmod 777 {} \;
   sudo find . -type f -exec chmod 777 {} \;
7. Restart Server
   sudo /etc/init.d/proftpd restart

This got me up and running, I could add users and lock them into to sub-folders without much hassle other than repeating steps 3 and 4 with a different path.