If I add an SSD, do I have to move my OS (Windows 10) to it and my DAW software and its related files? I'm not hugely techie, so I'm not quite sure how to go about adding an SSD to take advantage of the processing speed.

Thanks. Carry on!

You will need software to clone your OS to your new SSD (eg. Macrium, Acronis)
Then your OS is very snappy and boot up time very quick etc . . .
If it's a really large SSD (over 500GB) and you have a lot of large sample libraries, you might find the advantage of putting samples there, then loading the libraries will be much quicker for opening projects. There's no huge advantage to having your project files on an SSD.

I recently did the upgrade myself to a Samsung 850 EVO, 1TB drive. It came with the software to clone my old hard drive, and it was a pretty easy, painless process.  After I did it I realized I was really only using about 300GB on the boot drive, so I partitioned it using a utility called EaseUS to a little over 400GB for  boot drive and the rest for samples.  I copied my Superior Drummer 3 libraries over to that partition so that it loads faster.

Put stuff on it.

I don't think partitioning a drive will improve speed. Your still using the same buss. The only reason for a partition is you could say re do the OS C partition and it would not change or delete the content in the DATA partition. 
 
I just re did my DAW last night with a Samsung Evo pro. I used a 250 GB black friday special  $100. new egg. 
 
All is up and running smooth again REAL FAST. My old SSD also a Samsung Evo was 3 years old, I think they slow down over time. Anyhow boot time less than 10 seconds now. I didn't realize how bogged down my DAW had become..
And for that reason I believe in a fresh start as apposed to cloning. Cloning is fast but it also brings back all the garbage that gets stashed. To me the speed you gain is worth the time. 
 
I started after dinner last night. By bedtime everything was up and running. 
I used my Windows 8.1 disk so no more W10 update blues for me. It took about an hour to finish updating so I was working on my other computer and keeping one eye on things through all this. 
First I installed my Scarlett  ASIO drivers and disabled all on board audio. 
Tweaked a few Windows settings.
I then installed CCC and transferred all my files from my back up drive to the download folder. 
This makes installing Sonar and all content go super fast. I think I was done in less than an hour. 
Then I dealt with my XLN and Pace installers and installed AD2 and all my Air VST's and Plugs. 
I put everything in the new C drive because it will only ever be used for Music.
It's sitting at 80 GB and 36 of that is my Air content.
All my working projects are on a second SSD. Then I have a 1 TB 7200 RPM Data drive for back up and archiving. 
 
This morning I installed Wave Lab, Gold Wave and Nero and the drivers for my Rland A 49 and DTX 450 drums. 
That's it, nice clean machine. Ran Sonar for an hour so far and only glitch is I can't remember how to get rid of the start screen. And so far no more NAG screen from XLN. 
 
 

To clarify, my only reason for partitioning is so that when i image my boot drive I'm not also backing up 300 or more GB of samples for not good reason.

When I ordered my latest computer, I specified two 1TB conventional drives and one 500 GB SSD, which I had intended to use for sample libraries. However, when the computer arrived they'd ignored my instructions and made the SSD the system drive. So the first thing I did was to reconfigure it to the way I'd intended.
 
However, after having had the SSD as the boot drive for just one week, I was dismayed by the performance of the conventional drive and moved the SSD back to being the O/S drive. I'd been spoiled that quickly by 5-second boot times! So even though 500 GB was much larger than I needed for the O/S, I put it back and vowed to add a second SSD for samples. I haven't done it yet; still waiting for 1TB SSDs to come down a little in price.
 
My plan, once I've acquired the second SSD, is to duplicate (rather than move) my samples to it. That way, existing projects can continue to reference the old drive while new projects can benefit from the SSD. Keeping the old sample tree in place also assures a hot backup just in case there's an issue with the SSD. Of course, I'll also keep my 3 TB external drive that contains copies of all the virtual instruments as well as projects and an Acronis image of the whole system.
 
What I didn't want to do is use the SSD as my paging device (which would reduce its lifespan), so I moved paging to the conventional drives, splitting it between the two. I have enough RAM (16 GB) that paging overhead doesn't have much impact on overall performance.
 
Another thing I did was to move all my Cakewalk samples off the C: drive onto conventional drive D:. These I implemented via symbolic links, in order to avoid having to reconfigure or reinstall any of the Cakewalk instruments. This step wasn't really necessary, since I have plenty of space on the SSD, but I wanted all samples in one place for ease of backup.
 
Regarding partitioning, I don't know this for a fact but I suspect that SSDs may not suffer the performance reduction seen after partitioning conventional drives. That's because partitioning a drive increases average mechanical seek times, and SSDs do not have read/write heads.

What I read was the speed is limited by the SATA conection so 2 physical drives will perform faster than a partitioned drive because they don't share a SATA port. ANd I do beleieve different Mobo's have different set ups for those SATA ports.. mine has  2 regular and 4 marked Express?   I find the SSD are just plain fast and copying files between a SSD and a USB 3 external drive is  amazingingly fast. No more going and make coffee when transfering 30 GB. 

Linked directories is the way to go.

You move your folders you want to be fast to the ssd and leave a link behind in the old location.

Cactus Music, having HDD's on different channels definitely helps. If there are multiple accesses going on one is not having to wait for the drive head having to seek and reseek within the same drive. Plus, it also gives 2 or more parallel data channels.
 
With SSD's, I'm not sure it makes a lot of difference but having the ability for multiple parallel random accesses can't hurt. I have a 500gb SSD for the OS and program files and a 250gb SSD for the windows swap file, temp files plus some other shtuff. Unzipping to and from SSD's is crazy fast.
 
Then, there are the 20TB of HDD's for everything else.