This assumes that you already have a Google analytics account. If not then I suggest you read Carson's tutorial Adding Google Analytics to Wordpress

These are the instructions at Google help http://support.google.com/webmasters/bin/answer.py?hl=en&answer=183669

To submit a Sitemap:
1. Upload your Sitemap (or mRSS feed) to your site.
2. On the Webmaster Tools home page, click the site you want.
3. Under Site configuration, click Sitemaps.
4. Click the Add/Test Sitemap button.
5. In the text box, complete the path to your Sitemap (for example, if your Sitemap is at http://www.example.com/sitemap.xml, type sitemap.xml).
6. Click Submit Sitemap.

This is what you will get at stage 5

If everything is OK than you will be told that by Google. Congratulations.

If you have any queries please use the comments section or contact me directly. The plugin I use seems to have limited support now and I would be interested to hear about other people's choices.

Whichever you choose to use the principle is generally the same throughout however.