Are you talking about your own website? Such as a self hosted wordpress blog?

In that case , each blog post is a separate page even though they are all seen on the main page. Test it like this: See if by clicking on the title of your blog post, you can see only that post alone , if you can then each blog post is separate.

I assume you are using Wordpress which categories it's dashboard into "Posts" and "Pages".

While the exact number of pages it takes to create an authority site is not known (more of a gradual process, and depends on other existing authority blogs in the niche), 100 posts will count as 100 seperate pages.

As long as each post has it's own individual URL, it is indexed as a seperate page in Google. - Of course, that is if the page is backlinked and/or considered good enough to be indexed.

On a typical WordPress site there are many different ways to access a post, eg: via tags, categories, archives, home page etc.

Each post has it's own page and is linked from the resources listed above.

However, don't make the mistake of thinking that quantity is what counts for an authority site. If you have 100 pages of crap content versus 10 pages of good quality content, the latter will be much better.

I plan on posting quality content and hoping I can come up with enough eventually to become an authoritative site. My definition of quality is content that is written with excellent punctuation, grammar, and overall writing skills. Plus the information needs to be something that the target audience will benefit from. A well written article that benefits the reader in some way...

Low quality content is something thrown together for the sole purpose of having content. There isn't much real information or research put into these types of articles. Most of the time this is done for spinning and mass submission in the hopes of getting backlinks.