Graphical Network Design Tool

I would like to create a useful network for my organization at current building which has lot of rooms. I need to know the better way how can I suggest to my seniors about the actual requirement of equipment and cabling in the building to established a network infrastructure. Any free software which will help me to develop graphical representation of the proposed network.


Suggestions:
http://www.cutedraw.com
http://dia-installer.sourceforge.net
http://www.gnome.org/projects/dia/
At this time, only one I could think that might work is auto cad (architect drawing software) or the usual adobe photoshop CS.

Laptop Battery Issue

I have Compaq Evo N600c Notebook. The status of battery is showing
only 3% remaining (charging) though it is not charging and stuck and
running on power source. Is there any way to figure out this problem.
Before a week it was charging up to 56% and stops there.