Questuion: Where can I find PSoC documentation?
Response: You can find the datasheets, application notes, product brochures, overviews, erratas, developer kit details and other related things online at following link
If you have installed PSoC Designer 5.0 and above, then you can find PSoC documentation in following folder.
"\Program Files\Cypress\PSoC Designer 5\Documentation"
You can also access these documents from the Help >> Documentation menu inside PSoC Designer.