You don't.

We don't display individual company logos on the maps on openstreetmap.org.

You can, however, create your own map based on the Openstreetmap data and display your company's location, using your logo as a marker it you want.

You can add a website tag. But no logos, neither in the database, nor external.

There is a helpful article on this topic here:

http://weait.com/content/control-appearance-your-business-openstreetmap

Particularly helpful if you want a map on your own website with your company logo on.

Thanks guys....

Hello again! I tried to upload image, but I do it unsuccessfully. I do not know where i'm wrong.
I tried to add tag website, but I don't see that in map.... grrrrrrrrr.....
Help me, please. Thanks!

you need to own a website for this (or you can host your own local site to test it). Uploading the icon depends on the the service you're using.

So the first question: do you own a website, if yes, who hosts it?

We have own site.

I believe your company is the galeb group: http://www.galeb.com/

do you have access at the site? e.g. can you change the texts?

if so, how do you do that?

Wooou, how you now that, where you find it?
OK, I have to talk to administrators, whether they can do it. I now go home, but I have tomorrow from 8am again here, so we can continue the communication, thank you very much for your helping me, but I was a bit clearer to what I should do.