I don't know how useful it could be, but here's my typical workflow.
1. Import RAW files into Lightroom.
2. Enable lens profile correction, if appropriate.
3. Crop, level, etc.
4. Check, correct, change white balance.
5. Adjust exposure if needed.
6. Work overall lighting, adjust highlights, darks, mid-tones, etc.
7. Adjust clarity, sharpness, vibrancy and color saturation if needed.
8. Go into tone mapping and globally adjust if needed.
9. Work individual color saturation if needed (grass is most common to pop the green).
10. Decrease noise as needed.
11. Export the file as jpg, then open in a 25" monitor and check the work.
12. Go back to Lightroom and make adjustments as needed based on looking at the big monitor.
Interestingly, I just got the Nik software plugins for Lightroom. Their workflow directions says work out the noise first. Here's their flow:
1. Use Dfine to reduce noise.
2. Go to HDR Efex or Viveza to develop an HDR look or to adjust light and color.
3. Go to Color Efex for color corrections.
4. Use Silver Efex if converting to B & W, if not, skip this.
5. Finish with Sharpener Pro to sharpen image.
What surprises me is that most software adjustments I've ever done always increase noise -- so I've always gone to noise reduction last. Nik advises doing it first.
Such is life, I guess.