If you are designing the model, make your drawings as "orthographic" views. Front, back, left side, right side, top, bottom. Graph paper is great for this, as you can make the different views the same size. Tutorials do help when learning to model. There are definitely right and wrong ways to do things. Speaking as a 3d modeler myself, tutorials are how I learned. Video tutorials are best, as you can see exactly how the model is made in real time. I learned to model straight from video tutorials. I use Milkshape 3d mostly. It's not free($35), but it's cheaper than 3ds Max and other modeling tools. Metasequoia is also good, and has more tools than Milkshape. I hate Google Sketchup as a modeling tool. It does wonky things with the model geometry.