Prima Games is the largest strategy guide publisher in the United States. They have made a number of Pikmin-related guides, with in-depth walkthroughs. On top of that, they also commonly include extra information about subjects in the series that isn't given anywhere else, like the scientific names of enemies in Pikmin. While they are deemed official by Nintendo, they do occasionally contain errors, so how canon their content is is debatable.
The Official Nintendo Player's Guide