Study note when playing with node.js
- session1/README.md (https://github.com/jayzeng/node-note/blob/master/session1/README.md)
- session2/README.md (https://github.com/jayzeng/node-note/blob/master/session2/README.md)
- session3/README.md (https://github.com/jayzeng/node-note/blob/master/session3/README.md)