Well, I'll just try make a short guide then ^^ from 40 and up.
The final build will be: http://www.wowhead.com/?talent=fheboxZMeVb0VzxMGot
At 40, I'd go with this build for most dps:8/23/0
then build it up, mostly in combat. so at 50 I'd be having:10/31/0
At 60, this would probably be what I'd go with:16/34/0
and at 70:19/42/0
Where (on the way from 60) I would end up combat fully first, and then the last in Assassination.
This build is mainly for leveling and instancing. So no stealth-additions and no backstabbing. So go for swords (or if you find some kickass maces.. but mainly, swords is easier to get)
This is only my thoughts, so its may not be the 100% best, but still somthing to think about and build from. Just arrange it to what you like the most.