Regardless of whether you decide to improve yourself through unguided study or guided study, if you want to make money from your new skill you will need credentials. A credential is something that tells a perfect stranger that you know how to perform your skill. Your college degree is a good example. A professional certification is another good example.
Some credentials are stronger than others. A bachelors degree from MIT is a “stronger” credential than bachelors degree from Backwoods University (I don’t want to offend anybody by stating a real university, but you know what I mean). Credential “strength” doesn’t mean one person is smarter or better at their skill than another, it just indicates that usually a degree’d graduate from MIT is going to perform better than a degree’d graduate from Backwoods U.
A credential can also be in the form of work examples. This is very popular in creative industries such as graphic design where it doesn’t matter where you learned it, but you need to demonstrate that you’ve learned it. Your credentials consist of a portfolio of your work.
Some other forms of credentials are: letters of reference from known entities confirming your proficiency at a task; a license; and solid work history (more on this in a moment). If you want to make money from your new skill you NEED some type of credentials.
In my case I have one type of credential and I’m going for another. I’m trying to become a programmer with my current employer. Because I’ve been a good employee with them and have a good reputation with our IT group they are willing to give me a shot. So my solid work history is my credential, in addition to the classes I’ve taken.
In addition to “solid work history” I’m going to be looking for a professional certification. Sun offers the SCJP (Sun Certified Java Programmer) certification, among others. Microsoft also offers MC (Microsoft Certified…) certifications as well. Regardless of what you are going to be learning seek out professional certifications and start building your portfolio as you learn it.