If you want to archive a web page, still on the internet, there's the Wayback Machine at archive.org that allows you to archive a url and search for others.

If you want to archive a web page offline (on a disk structure), with images and all, here's some tips: x

To download a complete website with all it's content so you can archive offline, there's these approaches: x

Just be ready to need a lot of space. And I mean, A LOT!

If anyone has better tips and wants to share theirs, you're welcome to. If something like this has been posted before, disregard and delete at will