Anyone with a simple suggestion on how to get a straight rip cut on the length of rough-cut lumber so I can run it through a table saw for specific width?

I usually take a straightedge board and temporarily attach it (on the ends with short deck screws) on top of the rough cut but off to one edge. Run it through the taple saw using that straight edge board against the fence. Adjust the fence so that you get the most width. Now take the straight edge board off and run it through the saw using the newly edged rough cut boarde against the fence.

I do a similar thing as redover but with one less step:

I set my fence for the narrowest measurement and rip off a sliver on one edge. Even though both sides may be rough-cut and slightly wavy, over the length of a 2 foot fence it will even out. After the first rip, you will then have one smooth, straight edge unless the original piece was warped over a longer length than the fence size.

You can then put the new straight edge against the fence and make your real rip.

Thanks for the suggestion, redoverfarm. I'm going to give it a try. Sure sounds like it a good method.