A common issue is to see new blocks not showing up after publishing the page they live on.
Blocks must be published before they will show up on a page. The latest version of Episerver.Labs.BlockEnhancements(which is a separate package) addresses this with a feature called smart publish which identifies blocks associated with the page and asks the user if the blocks should be published. This is not available by default and requires the addition of the Episerver.Labs.BlockEnhancements package. See below for more info.
New version of EPiServer.Labs.BlockEnhancements (v0.2.0)