In the past month and a half I've done two quilts like this - one I did by sewing large 4-patches, sewing into rows, then sewing 4P rows together (seams open) (see avatar). The other I did by sewing each individual row of squares, then sewing all rows together (seams to one side or the other). These were my first two quilts, ever.
I personally preferred the 4-patches and open seams. Some do not. It all comes down to your preference...so do this one one way, and next time you try it, try it a different way and see what works for you!