Yes, WordPress under its default settings will automatically ping update services which will notify search engines every time you publish or edit a new page or post.
If you look in the writing settings of the WordPress admin panel, on the bottom of the page you will see the options for update services. When you publish new post, WordPress automatically notifies the update services that you have listed in that box.
The default settings for WordPress only have one update service, which is http://rpc.pingomatic.com/. If this box is empty, you should add this link. Some people choose to add many more update services, but in my opinion it is unnecessary.
Pingomatic will notify Google, Yahoo, Bing and all of the other major search engines that there has been a change to your blog. The search engine spiders are then scheduled to visit your blog to crawl the new content.
When I publish a new post to my blog, for example, it usually only takes a few seconds for the Google spiders to come and crawl the new content. A subsequent search in Google will usually show that the new post has already been indexed within only a matter of a few minutes.
If you want to increase the exposure of your blog, I also recommend that you install the Jetpack plugin for WordPress and activate the “Enhanced Distribution” module.
This is another way to ensure that search engines and alternate distribution channels are pinged when you add new content to your blog. Although I’ve searched, I have been unable to find out exactly what channels WordPress uses to distribute with this plugin, but I reckon increased exposure is good exposure.