The most basic requirement for the search engine to work is that pages are getting indexed. That will not happen by just installing the plugin! You will have to set up in TypoScript that a certain page should be indexed. That is needed for several good reasons. First of all not all sites in a TYPO3 database might need indexing. So therefore we disable it on a per-site basis. Secondly a single site may have frames and in that case we need only index the page-object which actually shows the page content.
Lets say that you have a PAGE object called "page" (that is pretty typical), then you will have to set this config-option:
page.config.index_enable = 1
When this option is set you should begin to see your pages being indexed when they are shown next time. Remember that only cached pages are indexed!
This is documented in CONFIG section of the TSref. Please look there for further options. For instance indexing of external media can also be enabled there.
The plugin supports all system languages in TYPO3. Translation is done using the typo3.org tools.
If you want to use eg. danish language that will automatically be used if this option is set in your template (the value is the internal language key):
config.language = dk