Indeed, anatomy is tricky. You don't really need anatomy to sketch quick portraits but for life drawing or drawing things from your imagination it's useful to have it stored away in the back of your mind. I was never very arty, just technically capable so I found a series called "The structure of man" really useful when I was doing a lot of drawing. If you are more artistically minded the Vlippu drawing manual is also great, you can find the PDF online (for free *wink* if you know where to look, if you can't find it send me a note).
Je deviens de plus en plus "humain" maintenant, avant de sortir de chez moi, aller poster un message sur un lieu d'echanges artistiques est pour une première etape x)