Hah, I didn’t even post it on my own WordPress installation! I wasn’t going to post it here (mainly because I forgot), but since I’ve been dugg (how exciting) after I submitted the link to Weblog Tools Collection (after I sent him an e-mail and, once again, FORGOT to include the link, yes I am an idiot).
I do really hope it’s useful.
Update: guess what? I forgot to link to it on this post as well. Here it is — How to turn a normal WordPress installation into a working online shop (without too many tears).