Sorting blog posts by author/tag

Hello,

I am new to wordpress and have an idea that i am not sure how to execute.

My website is for my company, we are small and just getting started and hope to use the blog to help drive traffic to the site. We have 4 people, each of us would like to be able to write. On the site we already have a section where we share links to our personal facebook/twitter etc and we would like to also include a link to our blog posts.

So for this to work I need to be able to sort the blog posts by author and create 4 pages to hold the 4 sets of sorted posts.

Additionally I would like to include a section on our home page where posts related to the topic of our company can be displayed. So for this i would like to add a tag or category to the posts and display only the posts with relevant tags on the homepage.l

Any help would be greatly appreciated. Thank you for reading.