Verification of your website is compulsory before you can submit your sitemap to Google, Yahoo and Bing. The verification can done easily using the Webmaster Tools as follow:
- Google Webmaster Central
- Yahoo Site Explorer (Yahoo Site Explorer has now merged with Bing Webmaster Tools)
- Bing Webmaster Tools
The verification will take place after you have inserted the verification meta tags (provided by Google, Yahoo and Bing) on your index or home page.
A FTP software will be required if you intend to do it by yourself. I will recommended FileZilla as it is free and easy to use.