Why don't you try from nautilus graphical interface for sharing? You can found sharing option to right click on an item in nautilus.
When you check on "Allow others to create and delete files in this folder" then anyone can edit and delete files in network but they need to know your samba username and password.
When anyone try to access your content he/she will be asked for your samba username and password. If he/she know the authentication information then he/she can see,edit and delete your content you share.
If you uncheck "Allow others....." then other (who knows authentication info) only see and copy the content but can not create or delete content.
If you want that Any one in the network can see your content the check the "Guest access ..." option. Where anyone can see the file without knowing your authentication information.
Add samba user in this file:
sudo gedit /etc/samba/smbusers
Format is = . So you can map your ubuntu username with different username for samba but this is not necessary. Example: say, your username is abc then add this line to /etc/samba/smbusers
<abc> = "<abc>"
Thats means anyone can access with abc username. you can use different name on right side.
Now set password for samba abc user (not your ubuntu user) password.
sudo smbpasswd -a username [abc]