The key to search engine optimizing a database driven site is in building splashpages which link into the database. These splash pages should have titles, h1 tags,content and inbound links relevant to the database result the page is linking to. For example if linking to a page about accommodation the splash page should haveaccommodation in the title, h1 tag, anchor text of links and in the content of the page. Then this splash page should link into the database results with the anchortext 'accommodation'. This way both the splash page and the results page are listed in Google, MSN and Yahoo!
The mod rewrite code is also a great way of making database results more friendly to the search engines. It is a great way of getting keywords into the URL of the pageand is also human friendly as well. A little time spent in implementing this code canresult in improved search engine results. I tested this on two of my sites, 1 with thecode and one without. The results: Both sites ended up getting the database resultspage indexed and page ranked but the mod rewrite site got there quicker!
In short there is no need to higher a specialist SEO professional to work on your database driven site you just need to be creative in showcasing the results to your potential visitors