I came across a really cool tutorial video about how to properly model the structure of a model. This applies to ALL 3D modeling, especially for games... it only really matters when you animate stuff or use specific modifiers or smooth things, but it's really important stuff.
http://www.youtube.com/watch?v=Ff6WnpPxtGQ
It's for Maya, but it's generic enough that you can understand all the important parts whether you're using Blender, Max, Cinema 4D or whatever.
Some tips:
1) "Append", a tool that's used to create a polygon between two edges, is called "Bridge Edge Loops" or "Make face" in Blender, and "Bridge" in 3DS Max.
2) Merge - in Blender the Merge is called the same, but you choose where you want to merge each time. In 3DS Max, the "Merge this vertex to that vertex" tool is called "Target Weld", and merging two vertices in their centerpoint can be accomplished with the "Collapse" button.
3) Making the model symmetrical - in Blender, add a "Mirror" modifier. In 3DS Max, add a "Symmetry" modifier. You might have to change the settings in the modifier to get it working right.