wp:archiving

You may be looking for:

Help:Archiving (plain and simple), an easy copy/paste of a single template appropriate for the vast majority of talk pages
Help:Archiving a talk page, a more comprehensive explanation of archiving templates with multiple options
Wikipedia:Link rot#Repairing a dead link, help with repairing dead links by adding web archives
Wikipedia:List of web archives on Wikipedia, a list of known web archiving services that can be used on wikipedia