Most journals publish a news feed (email alert or RSS feed) including the table of contents of the latest issue or the individual articles that have just been published online.
When available, this link is mentioned on the publisher website or on the journal website.
The site below provides a centralized approach to subscribing to scholarly journals tables of contents:
These alerts notify you when new articles related to a topic or matching a saved search strategy are added to the database.
The following databases provide this service if you register to create a personal account. If necessary, consult their help section for more information.
Most scientific or professional associations publish news about their activities. You can usually subscribe to this news by email or RSS feed.