To make anything with electronics you need an understanding of the relationship between voltage, current, resistance, and power. There are many sites out there for helping anyone learn electronics. Here are the sites that I regularly refer to:
http://hyperphysics.phy-astr.gsu.edu/hbase/hframe.html – Physics in a nutshell. This sight works as a roadmap to everything science. There are built in calculators and all sorts of examples throughout it.
http://www.falstad.com/circuit/ – Circuit simulator. Useful for learning and testing small circuits before attempting to build. This is great because there is no software to install, assuming you have Java. There are several programs (SPICE) out there that do a lot more than this, but this a great quick reference.
Forums: I am not an active member on any electronics forum but I know there are several out there. Depending on what level of understanding you are at or want to get to, you might consider looking into joining one.
School: As a last resort, pay someone to teach you. Try not to get too far into debt learning.