How can I add more than one pointer to a map?
You can use Get Location module for this functionality. It will create multiple location markers on a single map, with a popup bubble info and it comes up with inbuilt views. You just need to enable a block after installing it. Some more details about this module (from its project page):

... will provide Google maps API version 3 enabled maps on which to display markers of locations found in location-enabled content-types.
These can be displayed per node, eg &quot;/getlocations/node/xxx&quot; will display all the locations associated with that node. They can also be displayed per content-type, so if your content-type has a machine name 'venue' you can show them all with &quot;/getlocations/type/venue&quot; and it also supports paths like &quot;/getlocations/user/xxx&quot; and &quot;/getlocations/users&quot; for location-enabled users. These links have their own access permissions so control can be exercised on a per role basis.

If looking for custom thing, specify your complete requirement.