I do a multilingual blog. You can see the post in english OR in spanish. Originally, I tried to do in one language alone, but discovered I had very little audience. Mainly because I was in a Blog Challenge in english, but my main audience was in Mexico, so in wrote in spanish.
The option I tried then was to post in english and in spanish, alternating. But in the main page I had 10 posts, then 5 of them in english and 5 in spanish. I didn’t cover a week of material. It was no good solution.
I know that problem is also for people who live in Canada, country with two official languages, English and French. But also for people making business in Brazil, portuguese speaking country, but surrounded by spanish speaking nations. Or in all the European Union, in which to be successful you must use 5 or 10 languages in packages and web sites.
So, I founded the WordPress Multilingual plugin at http://wpml.org. They offered a plugin -used in this site- that allow you to make a post and then write in a subdirectory it’s version in other language. In this case, I do the spanish version first and then translate to english. You, as user, can switch the languages on the right column, at the very top. So, I regain 10 different posts on the main page, and my readers get their preferred language very easily -even if here and then there are menus or widgets in one language only-.
If you don’t have the time or the will to translate your site, the plugin comes incorporated a professional service at icanlocalize. Prices are affordable and the service very well to. So, for a little as U$0.07 for word, you can translate your site on 33 different languages. So, if you intend to have a multilingual blog, you can do it for free with the plugin, or very professional with the icanlocalize service.