This is a pretty simple view of some of the most common ones. Roche had a great poster and online viewer at https://web.expasy.org/pathways/ but that seems to be down. There was a community reconstruction effort at https://github.com/usnish/biochemical-pathways-poster.

If you are interested in anything specific though, the KEGG database is a great resource - the pathway overview map can be found here: https://www.kegg.jp/pathway/map01100