The base-level SketchUp is a simple soul - so it only has the sun, and it has no lights, no reflections, no refraction, no bump-maps, no caustics etc. BUT many of these can be 'added' to your SKP using special features of 3rd-party rendering applications, that then render the Scene more 'realistically' that base-level SketchUp.
SketchUp has never looked so good. LightUp is the fastest and simplest SketchUp renderer on the market. Thousands of professionals, from one-person architecture practices to movie-makers at Pixar, choose the LightUp plugin for SketchUp to instantly illuminate their models and show their work in the best possible light.
There are several free or inexpensive rendering-applications available. Many of them have 'free trials', perhaps with some limitation on exported image size and/or discreet watermarking. Some of these tools are easier to use than others - look in the Gallery for the vast range available.
As a newbie you probably don't want the 'all bells and whistles' features. There are several specialist threads listing and discussing render tools. I suggest you do a SCF Search and trawl through those. For example this and this both discuss 'renderers for a newbie'. Most render-tools also have their own sites which will offer more detailed advice, useful once you pick one or two to look into further.
![Sketchup Sketchup](/uploads/1/2/5/4/125489348/899201056.jpg)
At first, thanks very much for your quick and detailed answers. First point I know now, that Sketchup free Version isn't able to show lights, exept the sun.
I installed the Renderprogram Kerkythea, and tried already placing lights but I get no result, sometimes I have light, sometimes not. And I don't know, why, or where I can change the lumen or anything else (Is it right, that the light effect is only seen after rendering?). Also i searched alreay in the Internet for a Tutorial, but I don't find anything I understood the context. I have now a new toolbar (Kerkythea) in Sketchup, with two standard lights and the possibility, some others to import. But I don't know how to use So I need a short and easy step by step how to manage it.?