We are using SVN very successfully for source code in the traditional way: /branches, /trunk and /tags.
We do not use SVN for our art assets, which in a way are like source, but really don't have the same needs as source code.
I am referring to not only image files (jpeg, png, etc...) but also PhotoShop files and stock artwork that has been purchased (and shouldn't be lost).
What would be the best practice for file structure and procedure, for my graphic artists?
That's a good question actually. I'm wondering how other people are doing this.
What I usually do is keep track of main PSD files in the SVN repository in a separate folder. Let's say you have a /images containing all your images. In that case I usually set up an /images/source containing the latest PSD files.
It's a bit annoying on the first checkout, but PSD are not updated as often as source code so that's not too bad.
Of course you have to exclude these folders when you deploy your website.
Another way my company handle this is having all that on a network hard drive. We keep track of changes with a file structure like this:
/Project/Assets/Design/
/ Round 1
/ Round 2
/ Round n
The "Round" folder countain a version of the PSD files and the JPG exports associated to it. It is more efficient if you don't have too many rounds of changes, because if you have 100 revisions it's getting hard to manage correctly.