How do I make a "buy it now" link for a product that is in a "featured item", "Specials", and "New This Month" center box that is found on the front page?
These are in the admin but I can not attest to their function:

Admin > confuguration > Featured Listing > Display Product Buy Now Button
Same for other listings.

Another link I need to know how to make is a more info button that links to the items itself.
You should check the current function as even if there is not a more info, clicking the image and other areas of a listing takes you to the Product Info page.
Also does Zen cart have a function to display the first [x many] characters in a description field already built in or do I need to build my own.
This is also in the admin for several of the product screens like the product listing page:
Admin > configuration > product listing > Display Product Description

The last thing I want to have happen is a breaking of a table or a div that was put into the description and have it not be closed just because I did a substring.
Describe this in specific detail???