PvE Spec for Fresh 80?

Hey. I tried to search for threads like this but I couldn't find anything.

Anyways, like the title says, what spec should I be using as a fresh 80 level? At the moment I have combat / subtlety dual spec.

I know Combat is the best for PvE with gear. Considering I have green items & no ArP, should I still play combat or assasination first?

Thanks, and sorry for the noob question.

Ola. Assassination using dis spec http://wotlk.openwow.com/talent#f0ec0exoibofuAo0xV0hZx.

Cheers