A bit on softproofing:
(would have included it in the original post, but got a 'too many images' error, and adding it somewhere in the middle seemed a bit illogical)
What I'd do is this:
Open the image.
In the 'History' palette click the left icon in the bottom ("create new document from current state"). This gives you a duplicate called 'Open' to work on.
Softproof using the paper/printer profile.
Make an adjustment layer to correct the image (if needed), like Bruce Fraser described it here: "The Proof Setup simulation is "live" so you can work inside it. One technique I find effective is to use adjustment layers to optimize the image for a particular print process while working with the soft proof simulation turned on. I then save the adjustment layers in a layer set that's named descriptively for that print process. This allows me to make different optimizations for different print conditions, and turn them on and off as needed."
For instance, the next image, I could have used a hue/saturation adjustment layer, to get the blue/magenta tones in the upper left corner within Gamut.
Simply adjust the softproof, untill it looks as close to the original as possible and as good as can be. Use whatever adjustment layers you like: Selective color, curves, hue/sat.
Main point is, you don't want to permanentely alter the file, that's why you use adjustment layers. (Who knows, maybe you want to print it at a later date on a printer with a larger Gamut, or whatever)
Original top, soft proof bottom (Ilford paper profile, relative colorimetric. I didn't check 'paper white' and 'black ink' so something is left of the image )
Main problems are the upper left erea, and the skin tones loosing 'punch'.
Next the softproof after correction: While not identical to the original, a lot closer...
And the Gamut warning before and after correction:
Once you get it close enough, you can flatten the image, and then use Edit > Convert to profile (Edit > Mode > Convert to profile in CS), using the same settings you used in the soft proof. Save this file as a copy (filename_print_profilename.jpg or so).
Hope this helps...