Q: As a new Mac user is there a step by step guide for ex PC users

How about this for starters?

Switching from Windows to Mac:

http://support.apple.com/kb/HT2514?viewlocale=en_US

Sorry, forgot about the virus thing!

Shortest possible answer: there are no viruses for the Mac.

Explanation:

You may find this User Tip on Viruses, Trojan Detection and Removal, as well as general Internet Security and Privacy, useful:

https://discussions.apple.com/docs/DOC-2435

Sure:

Apple - Support - Switch 101

Mac OS X keyboard shortcuts

Keyboard shortcuts for Shut down, restart, and sleep

Many keyboard shortcuts in Windows are the same on a Mac except that on the Mac one uses the COMMAND key rather than the CTRL key.

Welcome to the Mac world. Adding to what the others have posted, but not having time to prune the list,  see these:

Switching from Windows to Mac OS X,
Basic Tutorials on using a Mac,
Mac 101: Mac Essentials,
Mac OS X keyboard shortcuts,
Anatomy of a Mac,
MacTips,
Switching to Mac Superguide, and
Switching to the Mac: The Missing Manual,
Snow Leopard Edition.&

Additionally, *Texas Mac Man* recommends:

Quick Assist,
Welcome to the Switch To A Mac Guides,
Take Control E-books, and
A guide for switching to a Mac

Caoimhin Mc wrote:

 

I am still getting used to even using the forum correctly !

I had another important query regarding transferring files, but probably best I start a new post.

You have got the hang of it!