Yep, as above - place it in the header or footer. Works on all my themes but obviously there are some very obscure ones that may not work.
I think this post will help you- http://noirtol.com/how-to-install-google-analytics-in-wordpress-site/
I think here is one post which can help you all. How to Set Up Google Analytics on Your Website : A Beginner's Guide http://www.thegeekyglobe.com/installing-google-analytics-in-wordpress-made-easy.html