I know it is so very tempting to install Magento onto a production server account, do the initial configurations, and launch your new store. I also know that if you're only working with one Magento installation, there will undoubtedly come a time when — no matter how careful you are — a buggy extension, an errant piece of code, or a mistyped tag will cause your site to "go dark." You may even experience the dreaded Magento error screen (well known for offering little advice or remedy).
Therefore, if you take no other advice in this book to heart, take this one seriously: create a staging environment.
Some developers, particularly those working for large enterprise operations, may want to create an elaborate remote development, staging, and production setup with matching hardware for each environment, to decrease the number of variables present when deploying and testing code. If you're working with a large team and you have the funds available...