Once you receive your images, it will be time to find/purchase a custom mat & frame or be lucky enough to find a pre-cut mat & frame at your local retailer. It is really dependant on the number of letters you purchased.
If you have to do a custom mat & frame, look for 50% off coupons at your local craft or framing store and this is a piece you will be thrilled to have in your home as an inexpensive piece of art.
IKEA has a frame for five 4 x 6 openings for $19.99.
You could also frame each letter individually (probably much cheaper) and hang side by side spelling your word.
Good luck & have fun!