For WordPress developers and designers to create a website powered by WordPress for non English clients is very easy. All you have to install the plugin like WordPress CML from Codecanyon and The WordPress Multilingual Plugin from ICanLocalize. If you want to put some effort in it than read these articles Localizing WordPress Themes and Plugins and How to Convert WordPress in Your Language.
A suite of wordpress plugins that cater for corporate multi-lingual websites. It allows specific country level user control, a detailed post revision mechanism and a host of other features.
You can: Set up the plugin with all the countries you want posts / pages translated into. Designate users as specific country level users, giving them access to only translate their own language. Allow a page / post to be published, while a newer version of the page is worked on in the background.
WPML makes it easy to run a multilingual website with a single WordPress install. Choose languages for your site and start translating content.
The default install comes with over 40 languages. You can also add your own language variants (like Canadian French or Mexican Spanish) using WPML’s languages editor.
You can arrange different language contents in the same domain (in language directories), in sub-domains or in completely different domains.
Simply install the TranslateThis Button plugin, and use either the widgetized sidebar or template tagto add the button to your blog.
The plugin comes with a wide variety of options that can be easily customized from your WordPress admin section. Includes controls for text & language options, various display settings and other functionality options.
References and Other Useful Resources:
2. How to make a translatable WordPress theme
3. Localizing WordPress Themes and Plugins
4. Translating WordPress Plugins & Themes
5. Localizing WordPress Themes
6. How to Translate a WordPress Theme
7. Translating the Hybrid theme
8. Localizing a WordPress Plugin Using poEdit
9. Multi Language WordPress Mobile Admin
10. WordPress in your Language
11. WordPress in Your Language
12. Translate a WordPress Theme in 3 Easy Steps
13. How To Change Language In WordPress Blog?
14. Translate WordPress site, plugins into several languages