I think I need to clarify here:
What I usually do with pix to be posted using photoshop - the cookbook approach:
1.Image/Image size I change the resolution from 300 my camera does to 72 b/c anything else on the web is useless. Changing this value will give me decent size of the picture (in pixles) and since for posting here I dont really care what exact size the picture is (as long as it gets my point over) - I leave it that way
2. Levels - I f the picture is ok quality, I just do Levels/Auto, typically thats enough, sometimes it needs more tinkering with RGB, but it is not common
3. Filter/Sharpen/Unsharp mask to something like 19%, 1 pixel, 0 treshhold will typically do the trick; again posting here is no art, all I am aiming for is a good enough picture
4. Changing quality - we speak jpg here of course - is the right approach to change thhe size, but instead of just quessing what quality it should be Save for Web gives me two or four previews of optimized quality and I can pick whatever suits me - changing the level of compression.
5. When I feel it is needed, I move the file from Mac to PC to see if it looks ok on PC too.
6. When I have more pictures to process - like the whole card - I run an Automate Batch of these steps on it and look at the results than go back if needed.
P.S. You are right with ppi being more correct - but I never heard anybody using it before. My job is DAM support for a staff of 60+ photoeditors; I quess it is just a quirk of the industry /forums/images/graemlins/grin.gif