Alerting services include a range of current awareness options such as getting journal tables of contents sent to your inbox; setting up topic, author, or journal searches for automatic updates; and using a RSS reader to bring together and organize research and news.
You can subscribe to get the table of contents of individual journals sent to your email or RSS reader. Generally, you can go directly to the publisher website and look for RSS or email alert links to choose from options such as most recent issue, specialty feeds, or even alerts for certain types of journal contents (eg. original research).
There are also services such as JournalTOCs - Journal Table of Contents Service, which find scholarly journal TOC's and export the RSS feeds straight to your reader.
RSS (also known as "Really Simple Syndication") is a way of keeping up with new content from webpages. Using an RSS feed reader (aka news aggregator), such as Google Play Newsstand, Outlook, FeedReader, etc., you can create a single location to check for updates from all your favourite blogs, websites, journals, news providers, and more. For staying current on clinical and research evidence, you can also create topic feeds based on searches in PubMed and other databases.
The following video provides a explanation of RSS in plain English: RSS in Plain English.