Development talk:Blocks
From MoodleDocs
At this part: "At this point our block should be capable of being automatically installed in Moodle and added to courses; visit your administration page to install it and after seeing it in action come back to continue our tutorial."
This is not clear since Moodle no longer has a single administration page.
More to the point would say to go to the /admin/index.php page for your Moodle install. On my latest version of Moodle 1.8 the link in the Administration block is labeled "Notifications".