There are a couple of things to check to see whether the setup has been configured properly.
- Can you post the relevant parts of your cd_storage_conf.xml ? Have you for instance configured the SearchDAOBundle.xml file in the storage configuration?
- Are all the relevant jar files placed in the lib directory of the deployer?
- Can you post your logback configuration for the deployer? Usually the error appears if you enable logging for the org.si4t.* namespace and the com.tridion.extensions.* namespace.
- I presume that the Solr instance is running and is accessible by the deployer? Are your configured cores loading properly?
I have written a bit about configuring SI4T/ Solr on this SI4T/Solr Configuration 101 page. If you have any questions, let me know. :)