Read the requirements below. It is preferable that we install a new theme for the blog, that covers the following requirements by default and then we can do little bit of customisation.
1. Blog home page, implement h tags correctly and few design modifications
2. Blog post - when you click on author name you will go to a page where you have author bio at the top and then all the posts from that author
3. guest authors will have limited access
4. Below each blog post there should be suggestion for related posts
Some more minor points will be there which we can discuss later.