For most of the current search engines (Google, Dogpile, MSN) there's very little you can do. When they find you, you get indexed. In order to get indexed the first time, your site must have a link from another site that they have already found.
The main exception to that rule is Yahoo, to which you can submit your site. We would recommend that you do so. Being listed on Yahoo guarantees that your site will be found by the other major search engines.
Another site to strongly consider submitting to is DMOZ.org, a publically-maintained directory. Adding your site to DMOZ.org will give your site at least one link from an external site. Find your category on DMOZ and click "Submit URL." Churches/Ministries can start here.
For Google, your rank in the search is determined by a number of factors, but mostly who you "associate with." In this case, that means who links to you. The more people that link to your site, the better your ranking will be.
In the end, the best thing you can do to help your page rank is to have a great site. If other websites are linking to your site and your site has a lot of good information on it, your site will rank better.
For a much more thorough explanation of Google's ranking system, visit this article.
Many people suggest that META tags are the key to search rankings. This was true several years ago, but is no longer the case. It does help slightly and certainly doesn't hurt. Use Site Preferences to add a "DESCRIPTION" and a "KEYWORD" meta tag. Make sure the values added are meaningful.
If you have concerns about search engines crawling a fully dynamic website, here is some additional information for you.
- We limit the number of querystring parameters which we use to generate most pages. Modern search engines (e.g., Google) will handle dynamic pages as long as they don't have too many parameters. Most pages on our site have three or less.
- Most pages on our customers' sites have a unique URL so that each page can be indexed properly.
- All of our sites include a straight-forward site map which help the crawlers find every page on your site. This site map can be submitted to Google or other search engines to help jumpstart the spidering process.
- Our business serves as a virtual network of sites which help increase each other's web rankings. Since most modern search engines use links to your website as a "vote" for your website, you can ensure that your site is "voted" for by at least one site. As our client list grows, so does our "reputation" with the search engines.