DelF

Here goes. I'm making a 14mm wide ring for an 8mm mast.
 
It's an idea to make sure the dividing table and the mill are reasonably centered. I use two pointy things and eyeball them from different angles until they look lined up.
 
 
 
Once that's done you won't touch the Y axis again. Zero the X axis by holding the wheel fixed (so the table doesn't move) with your right hand whilst rotating the numbered dial until it is set at '0'.
 

 
Prepare a piece of dowel. It needs to be wide enough diameter for the sheet material to sit firmly on it, and long enough for it to be gripped well by the table. This piece is 10mm X 30mm. Also make sure the end is cut flat and square - not a problem on your Byrne's saw!
 

 
Next get your sheet wood. It doesn't matter what size and shape it is so long as you can get your required diameter out of it, and of course it needs to be thick enough. I'm using a small scrap of pear - it's too thick but that'll be sorted on the mill. Just stick the dowel to the sheet with a blob of ca.
 

 
Next, put the dowel in the table and lock the jaws. Remember to leave a gap between the sheet of pear and the jaws - you don't want to end up milling your table!
 

 
I'm using a 3mm cutter here. I'm going to cut the outside of the ring first, and because my mill is at the centre at I need to move it 8.5mm before I can start, because 8.5 = the radius of the ring (7mm) plus half the diameter of the cutter. That puts the cutter just outside the required circle. So, that's 8 1/2 turns of the wheel on the X axis. 
 

 
To start cutting, unlock the table (using the little black knob on the front), switch on the mill and lower the cutter. I find it best to take 2 or 3 cuts rather than trying to do the whole thickness in one go. Now that the table is unlocked you can just rotate it carefully by hand:
 

 
I normally use both hand to rotate the table evenly but I needed one for the camera for this shot.
 
You'll know when you're right through as the outside piece will spin free - at that point stop the machine and break the scrap off.
 

 
I didn't film the next bit, but all I did was raise the cutter, move it back in 3mm, and lower it again to thin the ring down to the thickness I wanted. 
 
The final milling operation is to cut the inner hole. If you've followed the measurements so far, you'll see that in order to get the 8mm hole the cutter has to move back in another 3mm. It's then just a case of milling down just like you did for the outside diameter. In this example I knew when I'd got through because the sawdust changed colour - I'd hit the dowel!
 

 
Btw - this work creates a lot of dust - I really should have sorted out my dust extraction before I started. Please don't follow my example! 
 
I wasn't going to bother for this sample piece, but as the ring was still stuck to the dowel I decided to chuck it in the lathe (a drill would work equally well) to sand a slightly rounded profile.
 

 
Finally, I parted it off in the Byrne's saw and here it is:
 

 
 
I can assure you, it took a lot longer to photograph and describe this than to actually do it. 
 
I hope this helps - it would certainly be a good exercise to help you get familiar with your new machine.
 
Derek