Sometimes the best way to learn modeling, high or low poly is to just watch someone work from a video. There are many ways to arrive at the same outcome in modeling, but when you actually watch someone work first hand you really gain insight in the many ways you can manipulate the program and/or mesh.
From there you can launch into many different areas on your own. But make no mistake, learning how to 3d model is something that really never stops, there are always new tricks to the trade.
The better you become the more you discover more efficent ways to arrive at the same point, and efficent doesn't necessairly mean less polygons, it means understanding the programs and/or apps that you are trying to make handshake with each other and making that handshake successful.

Comitted to excellence through art.