Best Software Environment to create Image / Designs / Templates for Websites

Photoshop would be the very best. It is the industry standard, but is expensive at $999. This application has a learning curve. There are many. many videos and tutorials all over the web since so many people use it.

Another option would be adobe elements ($99). It is basically a lighter version of Photoshop. You can do a lot there are just some limitations when it comes to filters and effects. Great for wanting to do some quick projects.

Then there is a free GNU licensed graphics software called Gimp. It's a great program and you may find it does everything you need. You can't beat free. It is often referred to as the free Photoshop.

Here is a great resource for tutorials:
http://www.tutorialized.com/tutorials/Photoshop/Web-Layouts/1

whether Macromedia fireworks is different from what you say ?

also, i have Microsoft Web Expression 3.0 - Is it useful for me to create designs ?

Adobe Photoshop but you have to buy it
If u want to go for freeware GIMP is the best.

The Three Kings of web design...
Photoshop | Illustrator | Dreamweaver

By far, the best possible development tools for the job. There simply is no substitute.

As for tutorials, you will find literally TONS! of them for all three applications and all levels at the sites listed below.

http://www.tutorialized.com/
http://www.tutorialhero.com/
http://www.justdreamweaver.com/dreamweaver-tutorials.html
http://tutorialoutpost.com/tutorials/illustrator
http://www.good-tutorials.com/tutorials/photoshop

I hope this helps you, and I wish you luck.

Some of the best times I've had in Web Design was when I was learning and developing my skills.
Enjoy it!

1) I need to do complete design's like Image layout / Templates / Buttons / Icons

Please give me one URL for downloading a Design Environment.

What about Microsoft Web Expressions ?