I am new to 3DMAx 9, I model a head and applied UVW Unwrap, but when I applied the texture from the image from PSD, the texture showing at the front was also showing at the back. How do I applied the texture to cover the head properly.

Give us some pictures, right now its very hard to picture what you have said. You also explained it really badly. Sorry i couldnt be of more help, but really, you could have made it easier to understand the problem.

I HAVE UPLOADED THE IMAGES OF MY WORK SO YOU COULD SEE MY PROBLEM AND TELL THE POSSIBLE WAY TO USE THE UNWRAP.

You have probably used planar mapping... Try using cylindrical instead.
_________________
Andyba, 3d artist
skills: 3d modeling, texturing, rendering, 3d character animation, compositing
3d software experience: 3ds max, Maya, Softimage XSI, Deep Paint 3d, Body Paint 3D, Wings 3D, Z Brush
2d software experience: Adobe Photoshop, Adobe After effects, Macromedia Flash, Freehand

it doesn't seem to be that difficult...

I HAVE UPLOADED THE IMAGES OF MY WORK SO YOU COULD SEE MY PROBLEM AND TELL THE POSSIBLE WAY TO USE THE UNWRAP.

I think you placed the back side of the head on the face. You see when you import a texture into 3dsmax for unwrap, in the unwrap window you have more than one copy of the texture, it's now left for you to scale the unwrapped model to the size of ONE of the textures not two. I believe you placed the back side on another of the texture or you didn't flatten the map, hence you have both the front and the back on one texture. Try selecting all (CTRL+A) and flatten map your model.

I hope this post is helpful. Cheers.

I hope you would have solved ur problem by this time, still i would like to help u something i know. just go to ur unwrap modifier then edit and in the edit window click on the show map icon and in the drop down box select pick texture and select the uv map u have applied and it will show u the texture applied for each poly and then u can figure out the reason by yourself....

Good tutorial, accept it! Thank you

Have you ever considered using Mudbox or Z-Brush to paint on the texture? It'll save you a lot of hassle and it's a lot easier as you can also produce normal maps from it. Search for some tutorials on YouTube.