i would like to install linux,plz.. could u suggest me which software is better.

Are you sure you don't mean "distribution" instead of "software"?
And how would you define "better"?
Did you search LQ for similar threads?
Did you find and read the distribution megathread?
Have you tried any distributions already?
Ever heard of the term Live CD?

for what purpose you are planning to use Linux

Go to this site and fill-up their questionnaire:

http://polishlinux.org/choose/quiz/

This will suggest a suitable distribution for you. It might not give you the perfect answer, but you'll probably be happy to start with what it suggests.

Hallo, it seems you are a beginner.
I propose you try out some LiveCDs so you get familiar with Linux and get an idea what you want.

There are hundrets of distributions
I prefer Puppy because:
it is small, quickly, it works well on old but also on new hardware.
It has Software for nearly every common desktop duty included.
It is well documented via manual and various forums.

But you can also try
Openmamba (very good hardware dedection, good distribution for beginners)
SLAX (modular !)
GoboLinux (different file organisation, but extreemly easy)
Ubuntu (best documented)
Mandriva
Sabayon very big

You will find that there are different WindowsManager. You usually can change the view of them so that they become more like you want them.
You will see you will like one more then the others but will not find a real reason (because usually you can do everything with every distribution and they can also look very similarly after you changed the view).
The most commons are GNOME and KDE, but there are many more.

I don't know what you are really interested in. So best you really try a few distributions out and there will come up some more questions. We are willing to answer but clear up with you yourself what the question is. Then we will be able to understand you better and we answer according what you want to know.