For a quick start, you can look at Polylang, getting started PDF document. It will help you to setup your multilingual website step by step with a lot of screenshots. To go further, the full documentation is available below:
- Credits
- Contribute
- Setting up a WordPress multilingual site with Polylang
- Frequently asked questions
- Documentation for developers
Function reference
pll_the_languages
Use show list languages (flags, name).
<div class="languages"><ul><?php function_exists('pll_the_languages') ? pll_the_languages(array( 'show_flags' => 0, 'show_names' => 1, 'hide_current' => 1, )) : ''; ?></ul></div>
pll__ and pll_e
Use to translates a string previously registered with pll_register_string.
<div class="button"><a href="#back"><?php echo pll__('Back');?></a></div>
If you don’t want use ‘echo’:
<div class="button"><a href="#back"><?php pll_e('Back');?></a></div>
Full Document on polylang.wordpress.com