I have a Holley stealth ram intake setup and the 950 commander program and hardware (ecu/pcm) It's a 350, sportsman II iron heads, 24lb injectors, a 58mm TB, SLP mid-length headers with Y and a shift kit.

I am a beginner tuner but know the basics (don't go lean, watch timing etc) I have an innovative wide band O2 so I can watch my af ratios.

How good are the base tunes for our cars?
Does anyone recommend a specific base tune to start with other than what holley recommends?

 

Good luck with that, the Innovates are slow and inaccurate.
Here's proof.
Otherwise most of the Holley base tunes are o.k. they'll get you headed in the right direction. Your combo is pretty straight forward.

 

Where did you mount your wideband?

Driver's side bank, just below the header collector between 12:00 and 3:00?

 

Agreed. The base tunes are pretty close. Still going to need some work to get right for your car. I have one wideband in the drivers header right after the collector controlling the computer and a separate one after the y displaying on my gauge in the dash. Also not a fan of innovate. Had issues with it grounding properly, switched to an autometer unit and no more issues.