I shoot only RAW and my workflow is as follows:
1. Import directly from CF/SD card into Lightroom, using a pre-defined import preset that sets metadata, lens corrections, picture style, keywords, and makes a backup copy to an external drive during import (at this point I have 2 copies of each image, on different drives, before I even start editing).
2. Put card(s) back in camera, format it, put camera away.
3. First pass: identify selects and mark rejects for deletion.
4. 2nd pass: edit.
5. 3rd pass: set final star ratings now that editing is done.
6. Export as necessary using a pre-defined export preset for sending to model, uploading to website or Flickr, or anything else that I may be doing with the images.
7. Delete the jpgs I just exported.
8. From within LR, move (archive) all of the completed images to storage on my Windows Home Server in my basement. (My Home Server, in turn, backs itself up to an external array at 1am nightly, and to Windows Azure cloud storage at 2am nightly.)
Some thoughts:
* My folder structure is simple: \Year\Month (ex. 2013\07). I use this on both my editing PC and my Home Server archive. If you're managing your image library with LR and you're leveraging LR's capabilities (keywords, ratings, etc) then folders become largely unnecessary. I shot about 20,000 images last year and they're spread across a grand total of 12 folders.
* If you're shooting RAW there's no reason to keep jpg's you've edited/exported. OK maybe there's *some* reason, I do keep some of my top favorites in folders to use as desktop wallpapers and on my tablet for showing off. But, largely, there's no reason to hang on to jpg's.
* I have a script that runs monthly that purges files more than 6 months old off the external storage from step 1 to prevent it from continuously growing. This disk is simply my emergency backup location that images are written to during import; After 6 months those images would have long been edited, archived to my Home Server, backed up to external storage off my Home Server as well as backed up to Azure.
* My backup process is thorough and 100% automated. I never have to remember to do anything, I have 3 copies of each image, and one of those copies is offsite (Azure).