If you are designing a website and you want to have a solid backend Solr is an exceptional choice not only because its search capabilities and all the integration with the lucene ecosystem also because its capacity to shard your data and get very good response times.
But which is the best approach in order to migrate your data to Solr? If you have your data in MySQL you can use the DataImport plugin but personally I prefer to have more control in this part of the code in case I need to create special fields in indexing time. In case you want to avoid the data import handler you can use SolrJ. With this java client you can create your solr/lucene documents directly from your code.
If you are interested in a more detailed example I have an example on github where you will find all the steps to create a Solr index using as a source wikipedia documents: https://github.com/raimonbosch/wikimedia.solr.indexer