1. Lightbox 2: Images can make or break a blog as you well know from your experience with your own blog and from your perusal of other blogosphere stops. This nifty plugin uses Colorbox to overlay images in a lightbox. One advantage is that your users can view larger images without being taken to another page, streamlining their experience which they will most definitely appreciate. With this plugin you also have the option of auto-lightboxing all the images.
2. WP-Print: While going paperless is a great idea, sometimes your visitors will simply want to print something for easier access later. This plugin allows them to hit print and then go on to other parts of your blog, saving them time and perhaps encouraging deeper interaction with your site that may lead to the kind of conversions you want. This plugin is a freebie.
3. Akismet: Spammers are the bane of bloggers. This plugin will banish them and garner greater trust from those who read your blog. It’s good for nothing in terms of cost.
4. Smart 404: When a user gets a 404 error he or she might think your site is old, down or otherwise problematic when all that happened was a URL was miss-typed. Prevent click-aways by nipping in the bud many of these error messages. This plugin uses keywords from the requested URL to automatically redirect visitors to a page that matches most closely. It offers a very high success rate and it is yours for the asking.
5. WordPress Popular Posts: This will increase page reads and put your best stuff before your visitors by featuring it at the side of each page. This free widget offers great customization and usability.
6. W3 Total Cache: W3 Total Cache is the fastest and most complete WordPress performance optimization plugin. This talented plugin creates a static html pages from your dynamic blog and dishes out that page to users. This functionality allows pages to load faster because a static page is much lighter than a dynamic page and less expensive. There’s lots more this plugin will do for you.
7. Post Teaser: Rather than having to scroll below the fold to see a post this plugin allows them to see a preview of the post and provides a link to the full post. It costs nothing but will save your visitors hassle and earn you their appreciation.
8. Search Everything: Keep things smooth and easy for your visitors and they will continue coming back for more. Search Everything delivers additional search capabilities so they can easily find the content they want. The plugin accomplishes this by ramping up the default search on your WordPress blog so users can search every non-password protected page, tag, post, comment, category, taxonomy and much more.
9. Outbound Links: Users won’t leave your site when they click on an outbound link because this plugin will open it in a new window leaving your blog window open and available. Its free and easy.
10. Subscribe to Comments: Build community around your blog by inviting readers to choose to be notified by email when someone adds a comment. It offers your commenters a tailored approach to staying in the discussion. Download it for nothing and gain quite a bit.