i have vista and office on old laptop and was going to buy parallel and windows for mac but not sure wats best i manly used word and excel / access
In my experience OpenOffice (at least the spreadsheet) is somewhat buggy and crash-prone on OS X. Microsoft Office 2011 for Mac works a lot better, if you need that.
Another option is uploading your .doc and .xls files to Google Docs, which will convert them to compatible files within Google Apps. It can't handle everything but basic files it handles well:
Google Docs - create and edit documents online, for free. It also supports off line access to your files, although I haven't tested that.
Here is an important video for Windows-to-Mac switchers which briefly describes differences in minimizing vs hiding app windows:
MacMost Minimizing Windows Versus Hiding Apps
Also if you are accustomed to selecting a file and hitting the delete key in Windows, in OS X you hit CMD-delete.
On OS X the right mouse button doesn't work by default, instead you use Opt-click (press option key on keyboard and click). You can enable mouse right click under the upper left Apple menu->System Preferences->Mouse->Secondary Click.
Another fundamental difference is OS X apps have a menu bar that stays at the top of the screen. On Windows the menu bar follows the app window around. Get in the habit of checking the menu bar whenever you click on a new app.
Edit/add: in Finder, just select the file and press space bar for a quick preview of almost any file type: .doc, .xls, .pdf, video, photos, etc. While in Preview, press up/down arrows for next/previous file. Press space bar a 2nd time to close it.