Last year I took a tour of the "boneyard" of old Vegas signage. I thoroughly enjoyed it and was planning to make reservations again for June. The place is maybe a 15 minute walk north on LV Blvd from downtown. Currently tours are very limited because there's a lot going on. I found this terrific article linked to Neon Museum's web site. The article gives a lot of background on YESCO (the principle designer and maker of historic Vegas signage) and the new happenings at the Neon Museum. There are a bunch of great photographs.
Here's the link.
http://www.neonmuseum.org/news/news-article-modernism-mag.pdf