Okay say my blog pages and blog posts all have the URL of http://abcdefg.com/?page_id=9 instead of http://abcdefg.com/what_to_do_in Vegas.htm Which one ranks better in the search engines and if my wordpress is set to the top one with the Page ID in the URL, how do I change that? Thanks
Dan has a good checklist. But just to answer your question keyword rich URLs are better for SEO and also for getting people to click on your link when your site appears in search engine results
Yes for sure second one will rank better in SE's ... You can change it from your Settings -> Permalinks
Of Course 2nd URL. Here is a list of some useful SEO plugins from Wordpress: Wordpress XML Sitemaps All in One SEO Pack Social Bookmarks
URLs with keywords are the best. THe latter is certainly the best. I separate words with hyphens.. Make it easier for ppl to read