how to insert simple gmaps in a block
There are many ways you can do this. 


Go to maps.google.com, type in the address, get the link, then click the customize and preview embedded view. A popup should appear. Select the map size you want. Copy the html code and go to structure -> blocks -> add block, paste your code and select full html filter. And add your block to where you want it
Download the gmaps module and use it. By default is has a block created called location map



  The GMap module provides an interface to the Google Maps API within
  Drupal. It integrates with the Location module to provide users a
  clickable map for entering latitude and longitude, as well as to
  display maps of Drupal nodes and users. GMap can be used to create
  interactive maps with various map markers and content in map bubbles,
  taking advantage of Drupal's other content management features. The
  module also provides a Views display plugin which allows users to
  display the results of a view on a Google map.