I'm actually trying to learn new things...
I used SQL for a long time, using MySQL and recently discovered document-oriented databases.
I came across graph-databases & Neo4j and want to try it through NodeJS but I really don't get the point.
Should I use Neo4j coupled with another DB? Like storing my data into MySQL & relationships in Neo4j?
Or may I use Neo4j to store data (like posts)?
Neo4j is often used as the primary database, see https://github.com/thingdom/node-neo4j for a node.js driver. Also, depending on your use case, you can use it with MySQL in different scenarios for complex queries that take a long time in MySQL like recommendations and other path queries, see http://docs.neo4j.org/chunked/snapshot/data-modeling-examples.html for some interesting starting examples.
/peter