In order to optimize wordpress blog for better performance one need take care of below mentioned points:
1) Optimize wordpress database. You can do this using a plugin such as this one or you can do it directly from PHPMyAdmin.
2) Install a caching plugin such as WP-Cache or WP Super Cache.
3) Check website using this online tool. It will give valuable information on what modifications can be made in order to improve its performance.
4) Decrease the number of external and internal links on pages. Leave only the most important ones.