Lightroom can sort everything but it won't help if you want to copy files somewhere else.
I suggest that you do not use My Pictures. If fact, don't use My Documents. If possible, keep data files on a separate drive or partition. Apart from anything else, that means you don't include all your data files in a disk image of C: - assuming you do back up the data somewhere else and that you prefer a disk image to be just system and program files.
Anyway.....
Create a separate folder called Photos, then a subfolder called Originals.
Subdivide this by date, with the year first - e.g. a top level folder called 2008, then below this 2008-01, 2008-02, etc. You can divide it further by the day if you like.
You then move all your original files into the appropriate folder, before importing them into LR. Remember to tell LR to index in original location (or whatever the phrase is!) so it doesn't create duplicates.
If ever you want to find the original RAW file from a converted JPEG, you just look at the EXIF data for the date the photo was taken and you can go straight to the appropriate folder under Originals.
Just a suggestion - works for me (though I don't use Lightroom).
