I think "local" means local to a single machine, usually a personal computer such as a laptop. How will you have the second person add content to your computer? Of course there are ways, but if you are a newby then it is best to not delve into these more complex issues.

Wordpress separates content and presentation. Have the second person edit their content in text. When you release your site they can then add their own content from their prepared text.

Hi PaoloM and welcome to WebmasterWorld [webmasterworld.com]

There are a few ways to collaborate on projects. Because WP requires a login for people who have administrative privileges, it needs to be accessible remotely for both users. The simple way to do that would be to use wordress.com to create the blog 'online' but that limits your ability to keep it private until you agree it is ready to go live.

You had mentioned that it is still local so I am guessing you are using a stack install of WAMP (or MAMP/LAMP) - is that correct? That means another person would have remote access to your computer with your permission which is not the best way to collaborate generally. (unless maybe it is your sister and she really admires you).

You could do the same on a shared host to make going live as easy as possible. Why does it make sense to pay a host while you are just setting it up? Because that lets you allow remote access without compromising your own computer, without needing to know how to set up a server. Because you could control access to your blog until you want it to go public. Because there are challenges to moving a WP install that make it difficult to migrate from a desktop install where there is no domain to use internal URLs that are related to another installation later on your own domain.

When you tell us that you are a total newbie, I hesitate to suggest things that are challenging to today's typical webmasters. I can suggest that you visit the WordPress documentation [wordpress.org] and read there until it becomes clear before beginning. WP is a simple platform but it is a mistake to jump into it just because it is easy to use. A week or so of study can pay huge dividends in setting up a safe and smart WP site.