We generally use online translators to convert sites from one language to another, If it were a wordpress blog you can make available your blog in different different languages without the user needing to translate your blog using online language translator tools. qTranslate is wordpress plugin that does the work of your blog translation and provides buttons to access translations in each article. qTranslate currently comes with 4 languages already builtin – English, German, Simplified Chinese.
You can also add a new language to the plugin by entering the 2-Letter ISO Language Code.
Check out the Installation guide on how install the plugin.
Download qTranslate from here.
Check out the FAQ Section for any doubts.
NOTE : This plugin makes changes in your wordpress database ?
Answer from their FAQ Section
Yes, it does. When you access the Configuration page, it will check how long category names can be. WordPress’ default length is 55 characters, which is too short too handle multilingual content. Thats why qTranslate will change it to support up to 255 characters. It won’t alter the database if you already changed it to a different type like text to support even longer texts.
If you want to try this plugin, I suggest you first try it out on your local installation of WordPress and then on your live blog.