Modeling in quads or squares is faster and easier, add an edge loop there, extrude that poly-loop, bevel those edges, I couldn't imagine doing that with triangles.
The shape the edge loop creates does not have to be round. It just creates a "loop" around the the object, and where it intersects with other edges it creates new geometry needed to add detail. I highly recommend giving Maya a try. The interface is very visual, and as you get used to it you can turn off all the picture…
edge loops are your friends :) Its good you are approaching game art from this perspective though. learning the gnitty gritty of tris, edges, and verts is never a bad thing.
What IS that? How can an edge have a loop? :) EDIT: I googled it...and I didnt understand it. Sorry, my english wasn't able to master the description. While looking at some images: it has something to do with connecting multiple vertices to form round shapes? (Oh...I think thats wrong)