Everyone has something slightly different that works for them. Here's how I have mine set up. It's on a Mac, but the concepts should still hold on a PC.
High level concepts:
1) Archive things based on what's "finished," not based solely on dates.
2) Your external RAID drive is fine as an archive, but NOT adequate as a backup - even if it's mirroring two drives, you need an additional copy somewhere else, preferably off-site or in the cloud.
On my local disk, inside Pictures I have a folder called "Current work." This holds all the photos that I've taken but not yet processed, culled, and delivered. When I've finished and delivered a set, I will delete all the rejects, and move the whole folder onto the network Archive drive.
In the "Current Work" folder, I have lots of folders, one for each set or event or subject matter. I name the folders with subject matter and date (YYYYMMDD) so that I can easily identify them. I generally don't bother making several layers of nested folders in my Current Work folder, there are never more than about 2 dozen folders so I can see it all at a glance.
For instance, the Cabaret show I shot a couple weeks ago, the folder is named "BBB Cabaret 20150626 Sci-Fi" and my family trip is in a folder named "Carter Vacation 2015 Callaway"
By including the date and subject matter in the folder name, I can pretty easily tell what's in there.
By using the YYYYMMDD format on the date, when you sort alphabetically it will also sort it chronologically.
On my network drive, I have a folder called "Archive" which holds all the photos I've worked in the past - not necessarily sorted by year, just everything that's considered "done." In my Archive, I have some high-level folder names, for instance: Family & Friends; Stage Shows; Wedding Clients; Professional Clients. When I'm done processing and delivering a set, I'll drag the set's whole folder from Current Work (local drive) into the appropriate folder in the Archive folder (network drive).
Important: If you drag folders from within Lightroom's directory tree in the Library module, Lightroom will know where you moved them - even if you move them to a different drive. If you instead drag them around in Finder or Explorer, Lightroom won't know where you moved them, and it will put a [?] on the images until you jump through the hoops to tell it where you moved things.
In my Archive drive, I can still pretty easily find things, since I named the folders and files appropriately.
For instance, in the "Stage Shows" folder I have three years' worth of photos from the Big Bang Boom Cabaret, named as follows:
BBB Cabaret 20150529 Vaudeville
BBB Cabaret 20150424 Oscars
BBB Cabaret 20150327 Cabaret Live!
BBB Cabaret 20150227 Orient Express
... and so on going back to 2012. I can tell at a glance what the theme of the show was and the date. In the same "Stage Shows" top folder, I have a similar structure for a few different troupes that I photograph, and lots of one-offs, also named and dated.
In my "Family and Friends" folder I have vacation pictures in folders like this:
Carter Vacation 2015 Callaway
Carter Vacation 2014 Florida Keys
Carter Vacation 2013 St Augustine
Carter Vacation 2012 Florida Keys
OK, so how do you do your initial setup?
Hopefully your stuff is already pretty well organized, at least by date. BEFORE putting it all into Lightroom for the first time, go through and refine it if you can: Rename folders and rearrange them into a structure that makes sense to you. If you're already in Lightroom, make sure to rename and rearrange folders within Lightroom's Library module - that way it doesn't lose track.
If your stuff is just a huge mess, you can use the Lightroom library tools to help organize - the easiest is to select your whole catalog (near the top of the folders pane on the left) and sort it by date. From there, you can create new folders and drag files into those folders. You can also use the filter to sort by things like camera type & body, lens type, and all sorts of other metadata. So if you want to keep the pictures you took on your 5D3 separated from the crap your brother took on his Nikon Coolpix, you can certainly use the filter to separate them out.
Without knowing how your stuff is organized now - or if you're even using Lightroom - I can't really give specifics on getting it sorted for the first time.
Adding new stuff:
When you have new photos, use Lightroom's IMPORT dialog to get them off the card and into your Current Work folder. Within the Import dialog, you can rename the files to something meaningful, create a new folder that's named appropriately and in the right location, and add keywords. I find this to be way more streamlined than copying stuff manually then adding it to the catalog - however, some people like to pre-cull using a tool like Photo Mechanic or Faststone, before even starting up Lightroom.
On file naming:
In addition to putting files in a folder/tree location that makes sense, I also like to rename upon import, to a file name that makes sense. Using the File Naming pane in the Import dialog, I rename my files to Event_YYYYMMDD_Sequence.CR2
For instance, the Big Bang Boom Cabaret shows are named something like BBB_Cabaret_20150529_2689.CR2
By naming the file with a meaningful name, I can guess the contents of the file simply by looking at the filename, without ever opening or viewing it.
On keywording:
Lightroom's keywording can be powerful, if you make the most of it. Some people do, I don't, I just use the most basic of keywords. Some people dump all their files into a single folder, and just use the Lightroom keywords to keep them sorted and organized. For instance, some wildlife shooters will put species names into their keywords, so whenever they need a photo of a Yellow Crested Nuthatch, they just keyword-filter the whole photo library, and voila! every photo they've ever tagged as Yellow Crested Nuthatch, right at the fingertips. Note that Lightroom will propagate the keywords to some external hosts such as Flickr.
On collections:
Similarly, some people use Collections to organize and sort. Collections are like ... folders and filters mashed together. You can group photos into all sorts of different collections, regardless of what folder (or drive!) the original image file is located in. You can manually add to collections, or use Smart Collections which automatically show photos based on criteria you select - date, keyword, filename, star rating, focal length, etc.
Umm, that's all I have time to type right now. Any specific questions?
