Michael Gray has an excellent post about optimizing your WordPress page titles, post titles, and page slugs.
He gives his reasons for taking these titles and this slug
Page Title: Jamie Lynn Spears is Pregnant
Post Title: Jamie Lynn Spears is Pregnant
Page Slug: jamie-lynn-spears-is-pregnant
and changing them to these titles and this slug
Page Title: Jamie Lynn Spears is Pregnant and Having a Baby
Post Title: Britney Spears 16 Year Old Sister Jamie Lynn Has a Baby Bump
Page Slug: jamie-lynn-spears-baby-pregnant
Principles for WordPress Onpage Optimization
For page titles (aka title tags), the main thing to consider is adding keywords that people search for. Page titles are the most important on page SEO factor, so make sure to insert highly searched and/or low competition keywords in your page title. That’s why Michael has pregnant and having a baby in his page title even though it’s redundant. Also, you’ll need this SEO Title Plugin to change your page titles. WordPress normally takes your post title and also makes it your page title.
Post titles should be attractive and draw the reader in. These titles are shown on RSS feeds and they are the first words most visitors will notice on the page.
Optimizing the page slug is not difficult. Make sure it’s not too long because long URLs are ugly and look spammy. However, try to add as many keywords as you can while keeping it short. Most people don’t look closely at the URL so you can take out non-keywords like is, are, with, and by.
Check out Michael’s post to learn more about crafting page titles, post titles, and page slugs on your WordPress blog.
Where Can I Change My Titles and Slugs?
Here is a short video to show you where you can change your titles and slugs on WordPress.
Here is the link mentioned in the video.
Stephen Spencer’s SEO Title Plugin: http://www.netconcepts.com/seo-title-tag-plugin/