I have very little experience manipping real photos, so take any of my advice on the subject with a grain of salt. From what I have done, I can tell you that it's effectively the same as manipping drawn pics, only - as Mindwipe said - much, much harder.
You're going to want to use Gimp for this. Photoshop is actually much better, but my only experience is using Gimp, so that's what I'm using for the sake of this tutorial.
For the eyes, you're going to want to start by erasing the pupils. I'd recommend selecting the color from the whites of the eyes, then filling in the center of the pupil. From there, use the smudge tool to blend it in with the rest of the eye. If you're going for whitewash eyes, you're done. If you want spiral eyes, you've still got a lot to do.
Before you continue, make sure the layer has transparency turned on. Just select the "Layer" dropdown menu, hover over "Transparency", and if it's selectable, click on "Add Alpha Channel."
Use the fuzzy select tool to select the whitewashed eyes. You'll probably have to muss around with the threshold settings, you don't want to select too little or too much. Cut the eyes, and create a new layer underneath the current one. Paste them onto the new layer. Because the fuzzy select's not perfect, there's going to be some transparent bits around the whites of the eyes. Smudge the sides of the bottom layer around to get rid of that.
Now you're going to want to find a spiral of your choice. I generally just type "spiral" into Google image search and scroll around until I find one I like. Once you've got one, create a new layer inbetween the two you've got and paste the spiral into it. If the spiral is white and black (or white and any other color) remove the white bits via the fuzzy select tool. Once you've done that, create a second copy of it. Use the perspective tool to shrink one of the spirals down until it's the size you want, and angle it so that it looks natural on one of the eyes. Then take the second spiral, and perspective it up to fit the other eye. If you don't want to mess around with the perspective tool, the scale tool also works, but I find that it often makes the spirals look flat.
The final step is touching up any whites around the spiral. As I said, the fuzzy select is not perfect, so there are probably going to be some white artifacts around the sides of the eye. use the smudge tool to fix those up.
And voila! You've got spiral eyes.
I'm sure there are better methods, but this is the one I use. As for drool... you're on your own. I still haven't figured out how to make drool look decent on real photos.
I hope this tutorial made sense. If there are any parts you're unsure about, feel free to ask.