Which is the best flavor in Linux for Migrating from Windows to Linux. I would like to migrate about 150 desktops from Windows to Linux ... are there any steps to be followed in doing so.

Well I've just moved to Linux in late March. And I'm still a newbie

Switched only on my laptop. Not like 150 computers which you intend to do.

However. Done a little reading about different distros. I've been a Windows user for the last 17 years, so I'm not used to the terminal screen and compiling stuff. I was looking for a distro that:
A. Could do (nearly) everything in a graphical user interface.
B. Similar to Windows in usage.
C. And don't have the need to compile a lot of stuff yourself.
D. Ability to listen to music, and watch movies without much of a fuss.
E. Since I use my laptop as my daily computer. I wanted it to be a stable and solid affair.

I've decided to try Mint first. And that one has been running ever since. Using it with KDE. It fits the 5 criteria I've set for myself. It was very easy to install. And moving data over from my external hard disks wasn't a problem either. It's faster than Windows 7 ran. Software Manager makes installing software a breeze. So I'm happy

From what I've read. Late May Mint should release version 13 Currently I'm using version 12 which is supported to April next year.

if you are migrating MS windows desktop os (XP, Seven), i would suggest to you to use Ubuntu and it's latest version. Ubuntu have power, robust, Great user interface and lots of packages that also can solve your problems with software's and their alternatives.

Coming from M$ to Linux and asking what flavor Linux is the best, is like saying I am coming from horse & buggy to cars and which car should I buy. Everyone has their opinion and their own reasons for that opinion. The best way is to try several different ones, you can download and burn them for free or order several from OSDisc very inexpensively. It probably won't take too long before you will see which one or two of the distros seem be what you might like. Then stick with the one that seems to be the best fit for you for a while to make sure. Also each distro has their own user forum where you can get help that is specifically for your distribution. If you find your first choice isn't quite working out like you thought it would, it is very easy to save any data and install another distribution to try.
As to installing on 150 computers here is what I just did for 12 computers in our community lab. I set up a small /root partition, 6 GB, and a small /home partition, 1 GB, and installed Linux. I then applied all updates and installed the programs that we would be using. We have a sloooow internet connection and I only wanted to do the initial update and program installation once. Then I used Clonezilla that was on my Parted Magic CD to clone the two partitions to an external hard drive. I then partitioned all the hard drives to the actual size I needed for /root and for /home and then used Clonzilla to put the software onto each computer. Of course, I had a unique situation as these were all new computers and all the same. You probably don't have 150 computers all the same but there are different ways to speed up an install for 150 computers. As you are trying out the different versions to see which one seems best, you can ask for help in learning the different ways you can do a mass install. Good luck

My first reaction is that I would consider migrating ONE desktop first, then spend some time with it and make sure it meets your needs. Many Linux users try quite a few distros before settling down. I'd hate to see you doing that on 150 stations.....

If you like MOST things to work "out-of-the-box", then you cannot go wrong with Ubuntu or Mint. Beyond this, you might want to tell us how the computers will be used.

If this is like a business office that you are moving then your distro will be something like Red Hat, Fedora, CentOS, OpenSuSE, or Ubuntu. For these distribution you can hire support from the companies for your bussines. Beside that each distro comes already packed with lots of applications for business office like enviroments as well as home users.

If this is like a public library or a school computer lab or whatever the best thing to do will be post on here what are you planning to do so people can advice you better.

Good luck to you.

Personally I would recommend Kubuntu.

I used Ubuntu for around three years and have used KDE for about a year now. I find it much better for many reasons.

I would suggest that you try a few out. I find it best to have seperate home,root and swap partions so that if you want to change distro you don't have to lose all your stuff. At work I even had a spare root partition to install a newer verison of Kubuntu worked with my hardware.

What ever you do don't give up on Linux, it really is better! I was a harded Windows MS user for many years and was a .net developer. I have since seen the light and use Java now and last weekend completed a project to remove native Windows machine from our trading system.

Best of luck,

Ian