MapPress Easy Google Maps
Mappress is a flexible map plugin that uses Google’s Maps API v3. You can add multiple locations to a map, and the popup bubbles can contain html such as links and images. After you activate this plugin, each post page will have a map section to input locations. You can enter in multiple places of interest (POI) markers for each map. If the markers are not in the desired location, you can move them around in the map editor. There is a paid upgrade that allows custom map markers and usage with custom post types. If you need to import a csv full of post data along with map coordinates, use either Turbocsv or WP Ultimate CSV Importer.
5sec Gmap is a paid plugin ($10) that is simple to use: just place the “[gmap]location[/gmap]” anywhere in your post or widget to get back a map with a customizable marker. Although this plugin is simple, a big drawback is that 5sec Google Maps only supports one location/marker per map.
The Geo Mashup plugin allows you to save location data with your posts and also includes interactive Google Maps to display your data. For example, you can chart all the posts that have a location data added, then create a map on a single page with a marker for every location related to those posts. This mapping plug-in is a little more complicated compared to other options, but the support is very good. Further setup details are here, and you can also see a list of sites using Geo Mashups.
XML Google Maps
The XML Google Maps is a great map plugin that excels at working with geocoded images. Not only can you place Google Maps into your posts, you can also use a Google Earth file (kmz, kml) to generate the map as well. You can plot the photos from a Flickr Gallery onto a map using Flickr’s geoRSS feed. You can even link to a GPX-File from a GPS to display elevation charts and speed. All images in your media library that have been Geocoded (EXIF) can be displayed on a map by this plugin.
Points of Interest Auto Map
Poi Auto Map combines Google’s Maps and Places APIs to enable you to add highly interactive Point of Interest maps to your WordPress site. The plugin includes geolocation to automatically locate your visitors (it should be turned off if you’re not using it, as visitors will get requests to share their location).
Google Maps v3 Shortcode Plugin
This Google Maps plugin still works, but you should make a change to prevent it from being called on pages without maps: http://wordpress.org/support/topic/plugin-google-maps-v3-shortcode-deregister-plugin.
Comprehensive Google Maps
The Comprehensive Google Maps Plugin is simple and free, which must be part of the reason it’s so popular.
JetPack for WordPress
JetPack is a swiss army knife plugin that is actively developed by Automattic so that WordPress.org users have feature parity with WordPress.com users (who have JetPack installed by default). One useful feature is their shortcode embeds, which offers a googlemaps shortcode. More information is available here: http://en.support.wordpress.com/google-maps/. Note that you will need a WordPress.com account to use JetPack.
WordPress Themes with Google Maps Integration
Another way to get Google maps into your WordPress site is to use a theme that has Google Maps integrated. Travel themes almost always have Google Maps shortcodes, including the following themes: