Updating OpenStreetMap is incredibly easy. Create an account, click edit (iD, the javascript-based map editor, is intuitive and highly functional), make changes, click "save."

The hard part is learning how to map well. The documentation is fragmented: There's a multi-language wiki with a lot of inconsistencies in the translations. There are dozens of mailing lists for various regions and sub-topics. There are IRC channels. There's a web forum. There's a subreddit. There's a Stack-Overflow-style Q&A help site. There are Youtube videos. And you can often find a different answer to a simple question in each of these resources! A little chaotic. But I wouldn't quite call it painful.