When I load my photos to my computer, I use Microsoft's photo uploader (which automatically triggers when you plug in a USB device or memory card to a USB input) to give the photos themselves a name based on subject and date. For example: Disney Dec08 001, Disney Dec08 002, etc. It's a batch uploader, so it names all the photos with the name you assign and adds sequential numbers to them.
You also choose what folder they load to - I have always been a user of MS Windows for a long time, and folders are just real easy for me to understand and work with - so I keep it simple and just use the Windows folders and subfolders to stay organized. For each new batch, I'll make a new folder (Disney Dec08, Disney Jul08, Wakodahatchee Nov08, Key West Mar08, etc). All the photos from that upload go into that folder. Then, I open a new subfolder called 'processed'. As I work on any photos and modify, crop, and process them, I save the new processed version to that subfolder. This ends up being the 'final' version folder that I would slideshow to friends and family, as it has been culled of any unneeded duplicates or bad photos. This has the added advantage of leaving all of my originals untouched, in case I ever want to go back and reprocess a photo or try a new technique on it.
Once a subject gets to be fairly common, and I end up with alot of folders on that topic, I'll grab all of the folders with the same subject (Disney, Cruises, etc.) and put them in a master folder. So I can click on photos/disney/disney dec08, for example, to get to the photos I took a few weeks ago.
I also use the subfolder system for places where I go often enough that individual folders for each trip would be a little too busy - I frequent a wetlands area for much of my bird and wildlife shooting, called Wakodahatchee. If I added a new folder for every trip out there, I'd have hundreds of subfolders. So instead, I have a master folder (Wakodahatchee), then subfolders separated by date ranges (Jan-Jun 08, Jul-Dec 08, etc). Each has a 'processed' folder within as well.
Having the larger folder topics is useful for 'stray' photos - let's say I took 5 shots of my Grandmother's xmas tree before going to Disney, and those 5 photos downloaded with the Disney pics. I can just drag those first 5 photos out of there, and put them in the 'Christmas' master folder, which is separated by subfolders for each year's Christmas.
Of course, once you've put all those photos in folders, and start to get alot of folders going, you can still use alternate photo organizing tools like Picasa to search and find photos to view for slideshows and such. Since all the photos are in a folder by subject and date, and all photos within are named by subject, date, and sequence, it makes it a breeze to find anything you need in seconds.
As for backing up - I don't move some photos to one drive, and others to another drive. I personally prefer to keep all my photos on a single drive, then backup that drive in its entirety to another mirrored drive, and also to an external drive...that way I've got 3 copies of my entire photo collection. Every so often, I'll burn some DVDs of my photos as another form of backup (not easy though when you've got 182GB of photos...takes alot of DVDs!). For those, I keep the previous burn, and just burn new DVDs of the most recent photos added. Once the DVDs get to 3 years old, I'll burn those contents again to a new DVD.