Adding outlets to an existing wall

I am working toward finishing our basement. Right now I need to add several outlets to an existing finished wall. I know that for a new wall I have to support/secure the romex 8" after the box and every 4-1/2' after that. What are the requirements for adding outlets to an existing wall. The wall is about 20' long so I plan on adding 2 outlets about 10' apart so it will meet the NEC receptacle spacing rules once I get that far.
Note: The finished wall is the back wall of the basement. It is finished because it is an above ground outside wall.

Thanks,
Mark

If you fish the cables, they might not need to be secured. See 334.30.

Also, go to an electrical supply store and buy the grey plastic single-gang boxes with screws (can't remember the manufacturer). These can be used both for remodel and new work. They are 10x better than regular remodel boxes.

Rick