I have the best luck with gluing down my borders before sewing. It helps stabilize them, plus I can make sure there are not any ripples before I sew them down.
What you see is literally what you will end up with.
Sometimes when you try to ease the top to fit the border and vice versa, you will end up with ripples. If you glue them first, you will be able to see where you might want to resew/adjust your seams here and there before sewing the final seam.
This tute works for blocks, borders and binding :wink:
http://www.quiltingboard.com/t-29275-1.htm