How could I get subsections, subsubsections, paragraphs, and subparagraphs (which I'll call "sections" from now on) that look like the one in this PDF file ?
In this PDF example, the indentation between one level of section and the next is too much, but the important point I would like to keep is that the name of the section (actually only its numbering) is detached to the left and the section content consists of one block to the right.
I guess there are some minipages involved, but i'm not sure how to use them to get the right result.
Thanks in advance !

titlesecpackage; something that sounds quite similar: How can I align section titles and list environments in the left margin? – cmhughes Dec 20 '12 at 23:08enumitemto get the spacings and the numbering as desired. And probably also the decoration of the first level titles. – Dec 21 '12 at 14:25