The following is a good, easy to follow guide written by Richard Steenbergen of nLayer (in PDF format).
It explains how a traceroute works, how to interpret the results and also the things that even trained network engineers in NOCs sometimes get wrong.
http://nanog.org/meetings/nanog45/pr...eroute_N45.pdf
Hopefully this will also give a better insight into things like "lost packets" that you may observe at various hops, including OVH's own routers.