Welcome to the world of PPR, first rule is that it typically shouldn't affect the top RB's that much, other than order.
My 12 teamer the first round went like this:
In our league QB's also get 1 point per 10 completions, 1 point for every 20 yards, 6 for TD, bonuses for 300 plus yard games and long TD's and we start 2.
So typically QB's go in first round.
The 2nd tier of RB's is where you see the PPR RB's pick up, Westy, Slaton, R. Brown, Bush.
Solid Catch guys are valuable to balance out big names, W. Welker is a WR1, as is Housh, Burleson is a nice sleeper WR, as he replaces B. Engram who was a monster in PPR in Seattle.
Backs like Washington, Sproles, Norwood and other 3rd down backs are ownable and can help in bye week pinches.
I would go RB, then try to get a nice WR on the way around, you can pick up backs like McFadden, Ward, Bradshaw later who could be nice RB 2's in a PPR league. QB's like Rivers, Cutler, Eli, Ryan, Schaub will be availible in the 5th or 6th rounds.
So try to go RB, WR, RB, WR, QB, RB/WR.
I waited till late, doubel digit rounds and got Shiancoe and Fasano as TE's, Zach Miller should be availible late as well.
QB: Brees, Rodgers, E. Manning
RB: D. Mcf, Grant, L. Wash, R. Rice, D. Brown
WR: Megatron, Driver, Hester, Ginn, N. Washington
TE: Shiancoe, Fasano
12 teams, PPR league