Adding pictures and/or videos is always a good idea. Videos create user interaction opportunities. With pictures, be sure to put your keyword in the alt text.

no it doesn't hurt your search engine ranking..

Two things: 1) google appears to count each photo as an indexed page, which is good for rankings; 2) You can add keywords to a photo as "alternate text" which is a chance to load some more keywords onto your site without being penalized for keyword stuffing.

Photos are win-win for on page SEO.

Yes, photos and pictures can increase rankings if placed in your posts.

Google is trying to give users a good search experience and when you have some images nicely formated with your text and sometimes optimized to your keywords you will rank higher, or at least have a stronger onpage optimization.

You can optimize your images to your keywords in a number of ways:

-Image name (keyword.png)
-Image title
-Image Alt tag
-Image Link (sometimes)

These factors all enhance your image to give a better SEO affect on your post.

Cheers,
Dave

Adding pictures actually enhances the presentation of your article and your overall website. Pictures and diagrams are also helpful when explaining subjects that are sometimes hard to explain with words alone.

Probably yes of course! Just be sure to put your keyword in the alt text to be more effective.

From user point of view, adding the pictures in-between the content is really good. Also, it would not affect your rankings. But for better results you should optimize your images with appropriate alt tags.