If you get high traffic to your blog then you must optimize WordPress and your server to run as efficiently as possible. This is very important and I have provided a step by step simple guide on how to do that. Follow and Implement. Let me know how this works out for you.
Part 1- SEO
1. Permalinks are important so make sure you set good ones which are visually attractive. /post-name
2. Change settings with Robots- Nofollow/noindex wp-admin, login pages, inappropriate categories etc.
4. Do not generate meta descriptions automatically. Write them yourself for better SEO.
5. Create proper pagination- WP-pagenavi might help.
6. Disable comments on Pages (About, Advertise, Contact etc).
Part 2- Speed
1. Install WP Super Cache.
2. Move .htaccess directives to your server config ( only if you have the option). Disable .htaccess parsing.
3. Combine CSS files into 1 big CSS file.
4. Make sure that Java script is loaded in the footer.
5. Use CSS Sprites.
6. Replace the all crappy plugins with the better ones available online, probably premium ones.
7. Switch to a better and faster hosting.
1. Use WP-dbmanager to backup your files frequently.
2. Optimize and backup your database everyday if possible.
3. Use anti-spam plugin to kill spam in your blog comments.
4. Remove any irrelevant and useless widgets.
5. Track your uptime. You can use several tools to do that.
6. Check for 404 errors and fix it using redirection. 404 notifier can be helpful.
7. Remove unnecessary meta tags, info or details.
Part 4- Social
1. Use good social plugins that will allow your readers to submit the posts they like. Good one would be, Digg Digg.
2. WP greet box is awesome. Use one on your blog and greet your visitors or turn them into subscribers.
3. Allow visitors to subscribe to your comments with a link or plugin.
4. Enable discus or gravatar to allow the readers display their avatars.
Part 5- Tracking/Analytics
1. Google analytics is the best so far and its free. You can use a plugin or insert the code in the footer section.
2. Signup with feedly to track your RSS.
3. Use a twitter analytic to track traffic from twitter.
4. Use Blog metric plugin and improve yourself everyday.
This is just a simple overview of what you should do. Its pure basic and I can go in depth and talk about each points in great details. Let me know if you want that. If you think I have missed any which are worth mentioning then feel free to add them in your comments.