I have been asked by a company to redevelop their website. A friend of mine installed WordPress in a folder on their hosting site. This allowed me to develop the site there. It is now ready to go and be moved to the companies hosting and replace the old site.
I have never done anything like this before and I am unsure how to proceed here to make this as smooth as possible.
Should I install WordPress in a directory on the companies web space and make sure the new site works properly there before replacing the old site with the new?
If that goes well, is it then a simple matter of moving the WordPress install and all files and folders to the root and deleting the old files and folders to get the new site up and running?
Also should I use a plugin to handle the 301 redirects or a .htaccess file.
I have never done any of this before so any help would be hugely appreciated.