1. Check the settings for Mysql on the subject of optimal in more detail: Optimum tuning of Mysql...
2. If the website content (i.e., few speakers on the page), be sure to use the cache, e.g. Varnish: Varnish - quick start
3. As the first in the queue will be the web server (better use nginx), make sure that you set it up: setup nginx for load
4. For basic validation under load, you can use ab from Apache
On the topic I recommend to read the history of the growth of different projects:highscalability.comhighload.com.uahabrahabr.ru/hub/hi