In my experience, it doesn't matter while lvling. The only thing i'd advise is to invest some into Toughness for when you plan to take on several mobs.
At lvl cap, it all depends on your build and what role you intend to fill.
Oh hello tempy, I so love bones. You want to grab them signets, maybe something like this! http://intothemists.com/calc/?build=...0;2JF04JF045Bh aim to get deeps strieks first and change fury to stamina. Although I heard this loses its effectivness around 60, Im no theory crafter though. Longbow and greatsword are my choices...er were my choices I never got above lvl 40.
power precision crit like most classes really... if you really want to focus on something try searching for a guide/build online most leveling builds seem to be 5 signet builds since the signet heal is the best or something..
For leveling, I find 5 signets to be really fast. The idea is to slice through them before they can do anything much, and with 75% crit (currently level 40 and that is my crit chance). It's not very good against champions, hard veteran mobs, and big groups of 4+ with ranged, because they live long enough to destroy you, since you are really squishy. If you do go for 5 signets, power/precision is common.