New template works but is method correct

I am very new to modx so excuse my lack of knowledge. I am a little confused as to the need to create a new folder for templates.

In the assets/templates/modxhost folder I have basically added my own .css file in here and added my images to the existing image folder, I have then pasted my template into the new template form on the admin section and in the head section of the html just changed the name os the .css file so it points at the one I uploaded. This all seems to work fine.
However in the tutorial it mentions about creating your own folder in the templates with your own images and css file contained in this, but now this is where i get lost, if I do this and delete the existing css file then it stops working.
Can anyone explain what I have missed and clear up my confusion.

Cheers

Ian

which tutorial? ...

The best practice is to duplicate the folder with all its contents, do same in manager with the template, and do the modifications to the newly created template. Ofcourse you will have to change the css and images paths in the template code accordingly. By doing this you wont lose original folder.

Thanks for the reply, the tutorial was this http://wiki.modxcms.com/index.php/Beginner%27s_Guide_to_MODx

I could see the instruction to change the [path to the css file but then as was not sure how to change the path to the images, however at least I know now that what am doing is fine, I am basically changing a site over to this excellent cms so it wont be a problem if I loose the original image folders.

Thanks for your help

Cheers

Ian