Okay so I'm a total beginner and I can't figure out this thing.

These are the simple instructions:

Add a plane (Space>>Add>>Mesh>>Plane) - (This will only work while the Mouse Cursor is positioned over the 3D View window).

I'm using Blender version 2.55 on my macbook pro. I hover over EVERY place possible, I press the spacebar and NOTHING but an option to search comes up ! It's frustrating as all hell and driving me insane!

By 3D View window, do they mean the main area I'm working in, because I've tried all around there.

I just want to make a freakin face. Can anyone please help by telling me exactly where to click and what button to use!?

That's because you are using blender 2.55
The instructions you were given are for 2.49b and earlier.
If I were you, I would use 2.49b
2.55 confuses the heck out of me :/

Thanks! I've been dying to have someone reply to me! :D
I happen to have downloaded 2.49 at the same time; so I will do as you say. Should I uninstall 2.55 first? Damn, the new version must have some pretty cool/ more advanced things — if you ever get a hang of it, let me know :]

Nah. I'd keep 2.55. I had another go last night and it's gradually becoming clearer. I'm currently modeling for someone's game so I'm staying with 2.49b because I can work so much quicker. If your just starting out, I'm not sure which you should go with. I would say 2.55 because it's up to date, but I'd say 2.49b, 'cos it's simpler and there are not that many 2.55 tutorials at the moment. Your choice :)