Rogue alt: need help with specc (only dungeons)

[Beeleth]

Hey all, i have a question and need help.. (searched but didnt find anything)
so, im going to exp a rogue alt with some friends, we are in four and we are going to exp only in dungeons..
I never played a rogue, so i would enjoy some tips on how to specc and wich wepons i should prefer (remember, only istances)..

Thanks in advance and excuse me for my english..

[Dharenna]

combat.