These instructions were tested in Kubuntu 8.10 (Ibex) but shall work with previous versions and future versions of Kubuntu and/or Ubuntu. Also I assume you want the share to be available to all users in the system so you need root access (i.e. sudo).
First install smbfs package:
sudo aptitude install smbfs
Create a directory were you want to mount the shared folder, any place is ok:
sudo mkdir /media/share
If the share requires username and password to access create a password file in you home directory:
sudo echo -e "username=my_username\npassword=my_password" > /root/.share_pass
sudo chown root:root /root
sudo chmod 700 /root/.share_pass
Replace "my_username" and "my_password" with the corresponding user and pass to access the remote share.
Finally create an entry in the "/etc/fstab" file to mount the shared folder in the desired mount point:
//ip-address/share /media/share credentials=/root/.share_pass,iocharset=utf8,file_mode=0777,dir_mode=0777 0 0
Here you must replace //ip-address/share with the ip address of the machine with the shared folder and the complete path to the respective folder.
Finally mount all partitions:
sudo mount -a
Now you must be able to access the shared folder at the remote machine by accessing the /media/share directory.