Which method of SOLR implementation should I use; 3 Questions?

[Gatete]

I have a classifieds website which I am now trying to integrate SOLR into, so searches becomes faster...I have currently Mysql as a db for all my records, and I use PHP to query it and display results.I have three main questions:If I was to implement SOLR, how is the standard way of doing it?And, I have not understood if I should update the SOLR index everytime a new classified is posted/or updated/changed, or index them all at once every 12 hours or so?Should I use SOLR to find the ID of the classifieds and then fetch the record in mysql, or should I use ONLY SOLR? I need some examples and advice on how to move forward, kindof stuck on this...I have read some great articles on how to use SOLR with PHP... But haven't found any good articles about dataImportHandlers if that's what I need..Thanks