I use Blender and I've no problems with it. Just takes a week or three to get used to the interface, which is confusing to a lot of people because it's very non-modular compared to other systems. A lot of other apps are actually 'borrowing' a lot of ideas from Blender's interface lately (the subdivided GUI, the non-modular design, etc). At least, that's what one guy at the Blender conference this year said. Maybe he was onto something, but regardless, Blender works great for me.
As far as tutorials, what you want to do is look for sites and artists that specifically target low-spec systems and just look at their meshes and UV's. I goto the polycount forums a lot just to check out the low-poly thread there (which is chock full of models that are all targeted ad DS, PSP and cell phone spec models mostly). Lots of models with fewer than 500 tris and 128x128 or smaller textures. Just study those guys and do a lot of practicing. Doing low low spec stuff will really help you understand how to make the most out of the silhouette and how to really define your shapes with as little geometry as possible.
Basically, the best way to learn it is to just do it, post it up and let people rip it apart. Lather, rinse and repeat.