thank you sir actually I am student of BS(Hons.) Bionfo & Biotech and Chimera was my presentation topic , Today was my presention and I do alot ..
I presented the following
1- Introduction to chimera
2-How to load a structure into chimera
   open  and  fetch
3- How to edit, select(chains, residues, atoms, also atom specifier), delete, 
4- Actions, zoom and drag , coloring and change the view of model (bonds, atoms, surface, ribbon, residues etc...) 
5-How to make animations
6-How to use commands
7-How to save animation in movie file and in accession file
8- How to align and superimpose two or more model structures and then their sequences and how to check RMSD
9-How to make or built a structure from peptide or amino acid sequence , and how to get or show the sequnce from protein model
10-How to make Ramachandran Plot
11-How to save high defination image
12-How adjust bonding
13-How to make solvate model 
14-How to make userinterface of our own choice
15-How to select tow different atoms and then how to make bond between them
16-How to merg two different model into one
17-How to two find a conserved region in the structure by giving the conserved sequence as input
19-How to select and activate a specific model
20-How to move different objects by mouse 
21-How to split a model into its chains
22-How to close a specific model
23-commands
24-How to show the ligand surface
25-ViewDock check the binding between the ligand and receptor
26-How to check the resolution of PDB structure
27-How to measure volume and area
28-How to save selected part of model into another separate as a PDB file
29-analyzing metal ion coordination geometries
30-viewing controls (side view, camera, lighting, shining)
31-Find clashes and contacts
32-Docking with autodock vina ( ligand-receptor binding )

 thank you so much sir for helping......

--- On Tue, 4/9/13, Elaine Meng <meng@cgl.ucsf.edu> wrote:

From: Elaine Meng <meng@cgl.ucsf.edu>
Subject: building DNA
To: "Muhammad ALi" <muh.ali741@yahoo.com>
Cc: "chimera-users@cgl.ucsf.edu Mailing List" <chimera-users@cgl.ucsf.edu>
Date: Tuesday, April 9, 2013, 4:15 PM

On Apr 8, 2013, at 6:42 AM, Muhammad ALi wrote:

> hi
> can we make a DNA model with chimera???

Hello,
Although you can build very approximate DNA in Chimera with the "rna" command <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/rna.html>, the result is rough and mainly just for viewing.  If you are planning to do detailed modeling or further calculations with the DNA, I would recommend not using Chimera, but instead some other program.

For example, here are some web servers that I believe will build DNA:
<http://structure.usc.edu/make-na/>
<http://w3dna.rutgers.edu/index.php/rebuild>

Elaine
----------
Elaine C. Meng, Ph.D.
UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab
Department of Pharmaceutical Chemistry
University of California, San Francisco