Where to start to learn mapping?

[fscii]

Hi,
I've read the few docs and took a regular map from the game (user made) and was able to do noob stuff like drop a health pack or grenade etc.

What I want to do is make one of those air conditioners on a wall so you can shoot out of it but I can't figure out how. It seems pretty difficult.

I saw this thread:
http://forum.cubers.net/post-27282.html

and tried /newent 107 (to get the air conditioner) but nothing happens except "unknown entity type 107" :(

I don't seem to be able to select the wall itself just cubes on the floor?! Even if I can get the a/c to work how do I click it onto the wall?

(I see it has a matching ent # 60, one for inside and one for outside).

Can someone please give me a "walk through" on how to do such a simple task? Is there a noob-walkthrough on how to do this stuff anywhere?

Thanks in advance folks.