This is not really a tutorial, but a list of handy tricks you will probably use a lot when modeling.
1: Extrusion: to extrude, press EKEY in edit mode with the vertices selected, move and click to place the extrusion. You'll basically need this for every model in blender, without it, most models would be really hard to create.
2: Set Smooth: setting smooth will smoothen everything, without increasing the amount of polygons and vertices. You can use it for models with a smooth surface. To apply set smooth, select the mesh, go to the editing buttons (F9) and in the Links and Materials tab, press Set Smooth. If you press the Set Solid button, it will go back to normal.
3: Remove Double: when you remove double vertices, they will melt together, this is good for attaching things to each other. to remove double vertices, select the vertices, go to editing (F9) in edit mode, and in the Mesh tools tab, press Rem Doubl, the limit button next to it is the distance that the vertices have to have to be melted together.
Example use of these techniques:
Extrusion: http://www.geocities.com/gauravnawani/tutorials/beginner/a-vase-modeling.html (they explain subsurf here too, but I'd recommend set smooth, because it doesn't increase the number of polygons and subsurf does) http://biorust.com/index.php?page=tutorial_detail&tutid=77&lang=en
Remove Double: http://biorust.com/index.php?page=tutorial_detail&tutid=77&lang=en (same tutorial as in the extrusion section)
If you want to add more handy techniques, please add them.