You should search first. WordPress has a Blogger import filter: http://codex.wordpress.org/Importing_Content
There are lots of plugins to handle redirects and images: http://wordpress.org/extend/plugins/search.php?q=blogger&sort=
Answers on WPSE, too: http://wordpress.stackexchange.com/search?q=blogger+import
and, lastly: http://www.google.com/search?&q=blogger+migrate+wordpress
Basically, it involves exporting Blogger content, importing it via the WordPress import filter, moving/caching images, and then optionally redirecting traffic from Blogger to WP using 301 redirects in page templates at Blogger.
Note that plugin suggestions for this are out of bounds on WPSE, re: the FAQ wordpress.stackexchange.com/faq
Read the docs and feedback on the importer and plugins at and try them out.