I'm giving you a link:
http://quilting.about.com/od/finishi...lt_backing.htm
This is about.com Finishing your Quilt Quilt Backing.
I think this site is Wonderful for simple directions; it is quicker than buying a book at this time. If you want to buy a book, check out the Rodale series, at amazon.com for used books. Rodale is wonderfully illustrated. Gives you all the instructions, spells out all the terms...
Here are my own personal Best Tips:
1) Machine stitch your Quilt Top around all edges, within the quarter inch seam line. This prevents stretching, and you can better control flatness of pieced edges at the seamlines.
2) Fold your Backing into Half, then into Quarters, and use your Hot Iron to press in Perfect Crease Lines, so you know Exactly where the MIDDLE falls, in both directions, horizontal and vertical. Much better than chalk marks.
3) On your Quilt Top, Mark your Middle Points with 4 pins, (Top Center, Bottom Center, Left, and Right) which you will match up with the Perfect Crease Lines on the Quilt Back.
4) Ask for Help. Have a confident friend work from the other side of your 3 layers, and with both hands, smoothe, smoothe, smoothe your entire quilt working from center to sides, center to top and bottom, to ease out any extra batting or wrinkles... You will feel inconsistencies with your hands, one under the 3 layers, other hand on topside.
5) Pin, pin, pin, working from Center to sides.
Best of luck to you, your top is very impressive. It deserves to be finished and used.