To start with, I found a nice high resolution photo of the real sign and had a friend print it out on 11x17 paper. This was to be my template for the sign and the lettering. I started out with two 12x18 cakes. I used buttercream between the layers and carved it to scale based on the template.
Then I covered it with yellow fondant followed by a piece of white fondant that I cut to size. To do the lettering, I used that printed template from earlier. I used a peice of parchment paper as tracing paper. I traced the outlines of each letter. Then I rolled out some colored fondant and, using a sharp and pointed shaping tool, I traced over the outlines from the parchment paper placed over the fondant. This gave me a slight impression on the fondant that I used to cut out each letter. I ended up with this:
For the "Welcome" part, I baked some sugar cookies. I made the whole wheat sugar cookies because I was out of regular flour. I iced them with royal icing and then added the "Welcome" letters. For the cookies near the outside, there is some floral wire holding them up. For the lights surrounding the sign, I colored some buttercream to match the yellow fondant and, using a small star tip, I put a dab at 1-inch intervals around the sign. Then I put a silver dragee on to each star tipped dab. Here are some photos of the final cake: