Well... here's my overall workflow. I generally shoot only in RAW, btw. Ever since a backcountry trip to the Everglades where I shot JPEG and was seriously let down by the lack of latitude for adjustments, I went RAW and I'm never going back.
First off, I do very little in-camera deleting. When I'm taking photos, I've usually got plenty of 4GB cards on hand. Since I do landscapes and wildlife, I'm always always busy taking advantage of changing light conditions or tracking animals, insects, etc. Thus, I save all my deleting for post-processing. I can't think of a single time I've ever done any in-camera editing... there's really no editing I can do in-camera that I can't do better or more accurately in post-processing.
I upload all my photos to my PC using Adobe Photoshop Lightroom 3 which uses Adobe Camera RAW to render the NEFs. During this process I convert them all to DNG files and create at least one backup set. I don't bother with keeping the original NEF files, since they are of pretty limited usefulness to me. (I do all my copying and backing up in one shot so that I can just reformat my card before my next shoot... I hate having multiple shoots cluttered on one card).
After they are all uploaded, I do a quick scan through all of them and delete any blatant throw-aways. Any shot that is over-exposed, lacks sharpness, doesn't have great composition or otherwise lacks proper technical qualities is deleted. I keep only the over-exposed shots that are part of a bracketed set for HDR processing. Sometimes I hang onto under-exposed shots, as RAW can sometimes breathe life back into such photos... decisions in this respect are made on a photo by photo basis.
Then I go back through and run any HDR processing for bracketed sets using Photomatix. Usually I don't keep the original bracketed photos once I've re-imported the HDR TIFF file, as this would just fill up my disk unnecessarily fast. On occassion, I'll keep the neutral exposure of a bracketed, 3-photo set if it stands pretty well on its own.
After all HDR processing is done, I do another scan through the photos paying closer attention to sets of similar shots. In this scan I'm basically looking through each set of similar shots and choosing the best one. Sometimes I'll keep a few of each shot if they have differing qualities. But, as hard as it can sometimes be, I'm trying to narrow it down to one keeper for each set of similar photos.
By this time, I've culled anywhere from 60% to 95% of the original photos... this number varies considerably. Sometimes I've done a lot of experimenting and I'll only keep 20 or 30 photos per 250 originals. Other times, the deletion rate is much lower if the shooting conditions were ideal and/or I've captured a large variety of subjects. Since HDR brackets require 3 photos for every processed TIFF, deleting the original brackets also frees up much more space and greatly reduces the count of final keepers. Some people probably like to save the HDR brackets, but I just can't justify keeping 4 photos (the 3 DNGs and processed TIFF) for what is ultimately just one finished photograph.
Once all the deleting is done with, I begin my detailed processing including all necessary work at a 1:1 scale. This includes cropping, white balance/exposure/color/contrast adjustments, sharpening, noise reduction, lens correction, and any touch-ups. Some photos get more treatment than others... that's determined on a photo by photo basis. Occassionally, I will find that a certain photo that originally looked good actually exhibits certain flaws that weren't easy to find on my first two scans. Sometimes, for instance, a given photograph will exhibit way too much noise. Other times, the focus, despite seeming pretty solid at a 1:4 scale, just isn't so great upon closer examination. In those cases, I will delete the offending photo, further narrowing down my keepers.
After that, I'm left with my set of fully-processed keepers. Now onto the cataloging process. I go through each photograph and apply all appropriate keywording. Living things (animals, plants, fungi) are keyworded according to various levels of scientific classification down to the binomial name, and also any common names which are appropriate. Landscape keywording usually remains pretty general: "mountain", "river", "ocean", "sandbar", "lake", "forest", "beach","sand", etc, etc. I use other IPTC fields to contain specific scene and location information.
Ahhh... the final gratifying step... rating. Each photo is now fully-processed and keyworded and needs a "star"-rating from 1 to 5. I try not to get too involved in making decisions like this, usually just casually choosing a rating that feels right for each photo. I generally think of the ratings this way:
5 stars : The photograph should be pretty impressive. Any 5-star rated photograph is one that I feel will maintain its quality for years to come, even as I may get better equipment, improve my technique, or whatever. It should be what I consider a truly great photograph... only about 5%-10% of my catalog is composed of 5-star photographs. This rating is not applied lightly.
4 stars : The photograph should be pretty damn good... not exhibiting any technical flaws and with pretty good composition. These photos are really nice, but just don't quite make the 5-star rating. Nonetheless, many of the 4-star photos will make superb prints and occassionally 4-star photos will even get upgraded to 5-stars after I have some time to ruminate over it.
3 stars : Three star photos are a mixed batch. They are generally good photos, but not great. Definitely worth hanging on to, but nothing I'd want to put in my portfolio. Probably between 40% and 60% of my cataloged keepers are rated at three stars.
2 stars and 1 star: These are photos which are mostly just kept for posterity, usually until I can get some better photos to replace them with. Say, for instance, I go to State Park X after a morning of shooting elsewhere. The light just isn't great by the time I get there and the photos aren't really all that good, even if they are technically/compositionally sound. I'll usually still hang on to the better few of the litter and make them 1 to 2 star photos until I get out there again at a better time of day.
And, well, that about does it... from start to finish. The process is not all that fast, admittedly, but after doing it so many times I can bust it out relatively quickly. Overall, it usually takes about 1 to 4 hours for each shoot... on occasion it'll take a little longer if I get very involved in adjustments and do a big series of HDR brackets along with my individual exposures.
