Beginner

The Blender Bros have cornered the market in how to do hard surface modeling.  It's easy to see why with great tips from them like the video below.  He has several rules that he uses that make sense when modeling.

Modeling 6 principles Learn this first and modeling will be easier  1.Form 2.Detail 3.Scale 4.Adaptation 5.Reuse

Simple Tools to make most things. Bevel, Bevel modifier, Loop cut, and several tips.

From CgBoost Great ways to model things  

cg boost 100+ Tips to Boost Modeling in Blender -  ya i need to move from lw to blender for modeling

From Daniel Grove Photos Modeling tips

20+ Styles of 3D Modeling in 20 Minutes -  ya this guy goes over some good modeling style, good to see how he does it. 

https://www.kit-ops.com/- its a plug in and it allows you to drop in assets almost immediately with a search ability - if that's the case - producing sets and stuff should be very easy and quick.  Sounds like a great thing

Blender KIT OPS Transponder PART 2: Modeling -- requires the kitops plugin.  Love the decal part.

Using kit ops to model a phone thing.  Ah fbx supports multiple uv maps.  So don't export as obj

Intermediate

He goes over the modeling tools and describes how to use them.

Modeling A Medieval Village House -  its mostly building shapes, texting them and positioning them.  Good job though

How to Add Decals/Logos to Any Model in Blender - Bing video

Creating a Spaceship in Blender: A Mini-Course -  some how this guy uses displacement to put nurnies all over a ship and it looks fantastic!! He used some paid plugins.

Expert

Organic modeling a dragon.

 hard surface modeling example - very amazing work

Organic Modeling a 4 legged creature by blocking