For a prot dps set str>crit>ap>hit (get 6% +hit minimum first, though). Slow mh is good, off hand doesn't matter so much but the faster off hand will give you more consistant rage. For a 1h/shield dps set you would go with the above while substituting any high +block value items you have for big shield slams.
Dual wielding is somewhat gear dependant for effectiveness so it's still going to be hard to level up prot and do decent dps. MS/arms is easier to level with because as long as you keep your weapon up to date and half-decent other gear you're going to do OK. DW dps doesn't really shine until you can get your AP high enough while maintaining the 6% hit floor to start out-performing 2h with MS... and in both fury and prot are talents that scale very well with stats. Arms builds tend to have a more flat scaling so being arms in greens/lowblues tends to provide better results than fury or prot (for dpsing/soloing).
EDIT: if you're going to do a lot of solo questing I'd say spring for respec to an arms build. Get something with 3/3 TM. Probably a 33/5/13 build and then add points to prot as you level up. This will let you tank pretty well with the TM change and you'll have defiance while still having a much better solo dps capability. By 70 you'll have 33/5/23 or something like that which is still a solid tanking spec. You won't need full prot til you're doing heroics or raids to be honest.