On Blender, I have seen people having see-through surfaces. How do I do that?

If you are asking about wireframe render then, select the respective object goto materials tab in properties panel and enable the wire button. If there is no wire button in materials panel add a new material.

Hope this helps...

Blenjoy...

If you want to enable wireframe mode you do the following:

Press Z to enable wireframe mode

Press Z again to view normally

If you want to enable wireframe mode for a single object:

Select the object

Go to "Object" tab in the properties window

Go to the "display" area, and select "wire"

Hope this helped :)

You mean wireframe? or just setting the surface material to translucent?

This is not exactly what you are looking for:

http://www.blenderguru.com/how-to-make-puddles

This site is very helpful:

http://www.blender.org/education-help/tutorials/