Grab your first two rows, and flip the 2nd row over so that they're right sides together. Line up the centers of the first rings in each row and pin. Line up the outside edges (to the left of the center) and pin.
(NOTE: You might have noticed, but I wasn't paying attention and sewed melons along the bottom of the 2nd row when I wasn't supposed to. Since it won't technically hurt anything, I left them on. Just pretend they aren't there because it doesn't change anything about the assembly.)
Work your way over to the right side and pin.
Pin until you reach the end where your 2.5" x 2.5" intersection square is.
The top square should be 1/4" longer than the one on the bottom, so make sure you leave that part hanging off the end.
Stop sewing when you reach the seam at the end. You don't want to sew all the way to the end because you need those pieces hanging loose.
Once you have them lined up, start pinning the second rings together.
Once you have that end pinned, line up the centers of the second rings and pin. Now start pinning the rings together in the area in between the end and center.
When you reach the point where the intersection square is sewn to the end of the arc, make sure you fold back the tip of the center medallion so that it lines up properly (I have it pinned in one spot so that it won't move, but in the photo you can see I still need to line up the very tip of it by moving it down a little bit)
Finish pinning the rest of that section.
Remove sleeping dog from fabric, then proceed to next step...
Now pin the other half of the rings, remembering to work from the outside in (pin the outside edge and center first, then the in-between area) It should look like this when you're done pinning the 2nd rings together.
Flip the rows over, and before you start sewing, make sure the seam allowances are lying in opposite directions (to make the fabric lie as flat as possible).
When you're ready to start sewing the 2nd rings together, you want to start the seam a little bit ahead of where the 1st and 2nd rings meet. This is to make sure all four intersection squares are nice and secured together at the center.
When you're done sewing the 2nd rings together, it's a good idea to open the rows up and take a peek at the "right" side. That way you can see if everything lines up properly before you move on to the 3rd rings. Don't worry if the intersection looks a little bunched up, because the paper causes this. Once you finish the top and rip the paper off, the whole thing will lay a lot flatter.
Plus, it looks a lot better once it gets a good ironing. See?
Flip the rows back over the wrong side, and start working on the 3rd rings. Find the point where you stopped, and pivot the fabric at the intersection so you can start pinning the 3rd rings together.
You're going to pin and sew the 3rd and 4th rings together just like you did the first two.
And just in case you're wondering at this point, "is it normal for my fabric to be all twisted, bunched, and crazy while I sew?" Yes, it is normal. Embrace the madness!
When you're done sewing the rows together, you'll notice that the ends don't line up. That's okay - you should have 1/4" hanging out from two of your squares (my pink square is completely finished off and measures 2" x 2", while the blue squares are finished on only 3 sides and have 1/4" of extra fabric on the raw edge). The excess fabric will be hidden when you bind the quilt.
To finish your quilt top, you'll attach the remaining rows exactly the same way. It's easy once you get the first one under your belt, because the assembly is virtually the same for the rest. The 1st and 2nd rows correspond to the 3rd and 4th rows (1 and 3 are exactly the same, and 2 and 4 are very similar - the only difference is the melons on the bottom of row 4)
Here are some photos of my rows once they've been completely attached.