If you are using blogspot and you want to optimize it in search engine such as google, yahoo, MSN Bing you should use a sitemap generator tool.
Sitemap Generator of Digital Inspiration is very useful.
All you need to do is type the url and hit the create blogger sitemap. Once it was done, you can click the yahoo and bing to let these search engines know your web site update. Google on the other need to be added manually. Adding it will be in another post.