N or normal maps can be generated in Photoshop if you're using a recent CC version using Filter > 3D > Generate Normal Map. There are various techniques to prepare an image for generating good normal maps, it really depends on the variety of colors and the difference between light and dark colors in the image. The image you posted is a good example of what would generate a good normal map because there are basically two colors in the lefthand image (diffuse image), one light, one dark...for the most part, and not a wide range of colors, which could end up generating a normal map with height information not consistent with what the diffuse image captures. For example, if your diffuse texture is an image of brightly colored marbles of different shades, instead of your normal map ending up as several smooth, rounded bumps, it will take the differing color information and assign differing height information where the smooth rounded bumps should be. How to prepare your diffuse image is something you'll have to research on your own. There are hundreds of Photoshop tutorials out there that will help you with that. Also, there's a handful of sliders you can play with in the Photoshop normal map generator that will allow you to tweak the height information and dial in the effect you're looking for. There are also other tools you can use that have a greater array of adjustments you can apply. Awesome Bump is a good, open source tool I used for quite a while for creating normal maps, and it also has a function for generating S or specular maps, which I cover below.
S or specular maps are textures game engines use to determine how light is reflected on your textured object. Generally speaking, the brighter the color, the more reflective the texture will appear in game. Off the top of my head I can't say if there's a good way to create specular maps in Photoshop with just the click of a button. Again, there are several tutorials on YouTube that cover this topic. It mostly depends on what the texture is supposed to represent. It's not as simple as plugging in your diffuse image to use as specular information. A black glass texture would end up flat and dull in game if used as a specular map, whereas glass should be something that reflects a lot of light. A light wood texture would end up bright and shiny in game if used as a specular map, whereas wood should look dull and flat. You see where I'm going with this?
Here's a good, general knowledge tutorial on creating textures for video games that I found helpful when I was learning this stuff: