Directories, noindex,follow and the Big G

Is this something that should be used?

[jd01]

This nagging thought keeps crossing my mind - I run a 12K entry business directory, which has the type of business organized by state (all listings) and state zip codes. At present, I am the only one presenting this information, except for a .gov website, in an unbiased, unadvertised manner. The difference between my site and the one presented by the .gov site is mine is spiderable where the .gov is hidden behind a form. (People who need help use it, so it is kind of important to have it be spiderable.)

Unfortunately, all of the business are in the same niche, so the descriptions that list their services are similar. Not all of these businesses have all the same services, so the pages vary to some degree, but are still in the realm of similar.

The organization I am using is as follows:
1. Index pages of the directory based on the state the business is located in, and the name of each business listed on the page. Users can find full information about the business and/or their site by following the link to the page that has the listing.

2. Index pages (again by state) but on this page the links are to specific zip codes with the businesses in that zip code listed on the page, so if a person is looking for this type of business in a specific zip code (or city) they are able to find it.

I keep thinking I might confuse SE's into thinking this is spam, when the reality is it is a very important directory for those who need it.

My question is:
Should I noindex,follow the pages in the directory and let the index pages be indexed and followed? My thought is if I allow the SE's to follow the pages, but not index them, they should be able to determine what the site/directory is about, but will not be confused as to which pages they should index and show in the results?

I think by letting all the pages be indexed, SE's might be thinking I am trying to fill their results with a large number of pages and then consider this spamming - The site is well indexed and does well, just trying to prepare for the future.

Any feedback is much appreciated, and if there is any semi-official word I would really really appreciate that.

Justin

[jd01]

I asked this in the Google forum, because I wanted Google answers, not general answers - Don't really care what would be better for the garbage Y has promoted in this update and do great in MSN - So, please keep in mind this question is asked for effects in Google and how Google views the site and tags not any other SE.

Justin