A: "Build Something!"
Reading books and following tutorials are all well and good, but you are not going to fully understand what it takes to be a professional developers until you start creating full applications.
Don't worry about the design, or perfect architecture, just come up with a small idea and build it.
Have a homepage with 10 most recent posts
- Post can have many comments
- Only users can comment
- Users must be logged in to comment
- Only you (an admin) can log in and make posts. Or anyone else with credential.
- Use SSL to encrypt your login.
Extra credit:
- Posts can have tags. Harder than you think.
- Comments can have comments. This is harder than you think.
Extra extra credit:
- Implement it once using an SQL database. SQLite/MySQL/Postgres will be fine.
- Implement it using a NoSQL database. MongoDB will probably be the simplest.
You can also try cloning sites you like, such as Twitter, Facebook, Hacker News. Or maybe a text-mode game. Anything that you might think is cool.
Or a tool for reading from some API you like. What about a command-line tool for getting the weather report based on your IP?