First of all, it's alright to be very slow in the beginning. To be honest I wasn't expecting any update from you in the next 2-3 weeks - I don't mind you made this update at all, likewise we can guide you in the early steps.
A bunch of comments which are very likely to be of use:
- I know of a
good tutorial for making a realistic car wheel (some aspects might be different because it was made on an earlier version of Blender, but the core is the same). I suggest you use it as a strong inspiration for making the truck wheels (of course, you won't be making a BMW wheel in your case).
- I strongly suggest you use a mirror modifier, since more than 90% of the truck has a symmetry. It will cut down your modelling time a lot. I guess the only non-mirrored element would be the dashboard of the truck.
- The metal part covering the wheel could use a bit more geometry. It's up to you to see whether adding more subsurf is sufficient, or if you need to make a more detailed mesh.
- One thing I am unsure of: I don't know if parts of the planes you used for the front end of the truck bin are exactly overlapping some parts of the planes from the rest of the bin. If that is the case, you'll have to correct this. Whenever some planes are congruent, you're going to run into
z-fighting.
- To see things more clearly as you model, you can alternate with wireframe view by pressing z. Another option is, in the Properties tab of the 3d vewport, to tune the setting of the "background image" (namely, bring your image to front with limited opacity).
- In your wheel, you have some odd shading artifacts. I don't know if it's on purpose. In any case, whenever you see that kind of weird shading and you want to get rid of it (personally, getting rid of it is what I want 99% of the time), you simply need to add one extra loop cut.
- Some very basic tricks that I wished I had figured super-early (instead of discovering it after a few months) when you want to do precise modelling where different objects are in contact. For example, let's take the case of a situation where you want Object B resting on Object A:
a/ Select Object B bottom vertices, and then use "Cursor to Selection", return to object mode (still Object B selected) and use "Place origin to 3d cursor". Select Object A's top vertices, use "Cursor to Selection". Return to Object mode, select Object B and then "Selection to Cursor". You can apply this trick for countless situations.
b/ Select Object A's top vertices, then use "Cursor to Selected". Then go to Object B, select bottom vertices. Use the 3d cursor as the pivot point for transformation, and Scale-Z with 0 as the value. This technique does not really do the same as the previous one, but it's extremely useful for clamping geometry of an object onto that of another. Overall, the limitation for this technique is about the number of axes you can use (Global X, Y, Z, and Normal X, Y, Z), but I find that very useful.
Take your time with the modelling first, we'll see about the texturing later. I'd rather you go slowly and be crafty about the details for now. You'll begin to worry about speed after you complete your first scene
If you nevertheless want to learn bits about texturing, I think it will be best for you to learn texturing related to Cycles render directly, not the Blender Internal render (texturing methods are different). The difference between what you can achieve with Cycles and Blender Internal can be huge (if you browse my thread of Sector 5 slums, the early scenes where with Blender Internal, the later with Cycles, you can see the differences for yourself).
Keep it up, and if you need advice (even very noobish advice) don't hesitate to ask here.
