International Internet Preservation Consortium (IIPC) - The website contains several useful resources, including introductory material about web archiving, content about legal issues, case studies, reports and presentations, a bibliography (up to only 2009), collection development policies and a page listing tools and software.
University of North Texas (UNT) Libraries is well-known for its robust web archiving program. You can learn about their policies, processes and projects, including their participation in the End of Term projects, on their website (current up to 2014, with a condensed tools list).
The Community Owned Digital Preservation Tools Registry (COPTR) offers links to several web archiving tools for crawling as well as static capture, though it not complete nor regularly maintained.
The UK's National Archives offers web archiving guidance (2011) and a website which includes guidance for website creators and managers to make their content more capturable.
Contemporary tools and resources excluded from some of the resource lists above:
Webrecorderis a web archiving service anyone can use for free to save web pages:https://webrecorder.io/
Social Feed Manager is open source software that harvests social media data and web resources from Twitter, Tumblr, Flickr, and Sina Weibo.https://gwu-libraries.github.io/sfm-ui/
Documenting the Nowdevelops tools and builds community practices that support the ethical collection, use, and preservation of social media content.
Conifer is a web archiving service that creates an interactive copy of any web page that you browse, including content revealed by your interactions such as playing video and audio, scrolling, clicking buttons, and so forth. https://conifer.rhizome.org/
ArchivesSocial connects directly to social networks such as Facebook and Twitter to capture and preserve the content on your pages – ensuring you can easily respond to records requests.
For safekeeping: An automated preservation workflow for Archive-It content,Adriane Hanson, University of Georgia, from 2020 Archive-It Partner meeting [slides] [recording]