Sidebar Navigation on Posts – Disable or Sort by Date

I can only find discussion about the sidebar page navigation, but nothing on the same on posts. I’m using posts for my primary content because they have the nice element of a date, which allows them to sort nicely on lists. However, the current Sidebar Navigation seems to order them in reverse chronological order, meaning that if I click to left one post after another until I’m at the far left (the start of the book, so to speak), the post I see is the oldest, but if I click to right one post after another until I’m at the far right (the end of the book, so to speak), the post I see is the newest. This would be fine if I was writing a book from start to finish but blogs and my site the most relevant content is the newest not the oldest.

Can you help me understand how to:

1) Disable sidebar navigation on posts. I only see control for pages.
2) Reverse sort order from oldest – > newest to be newest -> oldest.

Thank you!