Inkscape Tutorial

• Quite a good list here
• This one is particularly fun
• This one is explaining the basic of nodes, and shape
  

Openclipart thumbnail

I couldnt find the option to add a thumbnail and couldnt find any help either.

But it was simple actually, just upload the png file
generated by a shell command like : for i in *.svg; do inkscape -f "$i" -e "$i.png" -w 80; done

And then put that png file in the first position and the thumbnail shows up