For those who have created custom search engines, here are some URL pattern (the method for specifying sites and pages to include in a search engine) info that the Google team has provided to further your knowledge on how to maximize this feature:

The simplest type of pattern is the URL of a specific page. You can use an asterisk (or star, in techie vernacular) as a wild card in your pattern to specify a swath of URLs by identifying their common characters. Here’s how it works: rather than add each page of www.site.com to your search engine, you can merely add www.site.com/* and we will include every URL that begins with www.site.com. Similarly, rather than individually adding each subdomain of site.com, you can use the star to include them all: *.site.com will apply to www.site.com, server.site.com, etc.

Another way to use patterns is to identify and distill common characters among a set of pages you’d like to include in your index. For example, if I know that all car review pages on my favorite consumer reviews site contain the words ‘car’ and ‘reviews’ in the URL, I can create the pattern www.reviewsite.com/*reviews*cars and include these pages. (I just need to be careful that only the pages I want contain these terms, or I may include more than I bargained for.) These types of patterns are especially useful when creating search refinements.

More of these tips on star or asterisk use in URL Patterns.