Before starting it's recommended to be familiar with the usage of Blender, because not all commands and methods are described fully detailed. These guides are ment to be more or less descriptions of common modelling and texturing techniques, explained with examples created with Blender, but hopefully also useful for other 3D modelling software.

Keyboard commands:
g Grab/Move, moves a selected Object
r Rotate, rotates a selected Object
s Scale, scales a selected Object

The selected object can be transformed with the mouse or the arrow keys. Additionally the axis can be defined, to transform the object only along this axis.
gx moves the object along the global X-axis
gx1.0 moves the object one Blenderunit along the global X-axis
gxx moves the object along the local X-axis

Keyboard commands:
Spacebar adds an object
a de-/select all objects
x deletes a selected object
p separates an object
n Transform Properties
Alt+m merge
Ctrl+j join
Tab switch Object Mode / Edit Mode
Num 7 topview Ctrl+Num 7 underside
Num 3 sideview Ctrl+Num 3 other side
Num 1 frontview Ctrl+Num 1 rearview
Num 5 switch orthographic / perspective view

This is only a small range of available commands to make a start possible. More detailed description (RMB, save as):
Object Mode hotkeys
Edit Mode hotkeys

For Windows users, the handling of the mouse may be uncomfortable using Blender for the first time. Objects are selected by RMB (Shift+RMB, to add ojects to the selection). b, Border select, to drag a selection box.
Placing the cursor in 3D View, the selected object can be viewed by holding Alt+LMB and moving the mouse.

More about using Blender can be found at Blender's Wiki.