Well you are off to a great start and doing really well
I myself am only a year and a half into Blender but I have worked through quite a few courses. My progress from the very first course I ever did back when I was new to both Blender and 3D in general, right through to what im working on at the moment is in my Polybook here : http://community.cgcookie.com/t/polybook-frikkr/5554
I have tried to give a little bit of info about what I learnt and my views on each course, along with a link and suggestions to other relevant courses. and you can see my personal results to see what outcome you can expect. It may help you decide where you want to go with your learning
Check out everybodys Polybooks on here, they are a great way to get inspired and see what everybody is up to
Also in regards to your model, I think its looking great , but I was speaking to Jody about it earlier as he was telling me all about the project and I was saying to watch those tubes that connect the joints, especially the elbow ones, as you may have issues if you rig it, unless they are intended to stretch. And the support holding the gun on the shoulder looks a bit flimsy to me. If it were me , I would make the torso A-symetrical by adding quite a large section to the gun shoulder so you can get a nice chunky gun on there and even rig it to come in and out of the armor.
Hope this helps