Silvery - 3:21 pm on Jul 16, 2010 (gmt 0)
You can only check the caching of pages in the main Google search results -- not within Google Maps. And, there's some indications that Google Maps' data store is separate from main Google, even though they share info.
Further, there is a big difference between the pages Google uses for citation merely through spidering, versus the data feeds they get directly from their formal data partnerships.
To answer your latest questions:
Dos: Follow Google Maps guidelines. Also follow Google's overall Webmaster Guidelines. Insure your company is listed with all major online directories. Do the many, classic tactics for improving site rankings through SEO.
Don'ts: Don't use long, abnormal Category names in Google Maps - use only phrases which describe the type of business, and don't include any city names or locality names in the Category. Don't use a spammy-looking business name as the title of the listing in Google Places - use the actual business name and use the same business name in all other directory listings on other sites. Use the same phone number on all sites. Don't do any other spammy behavior prohibited by webmaster guidelines.