Your web designer guy is an idiot if he thinks that image means anything.
- choose whether you want your board to look like this board or a traditional *chan board. Copy the contents of either mode_message or mode_image into the general kareha folder respectively.
- open up config.pl in notepad. Read the settings, change the ones you want, and remove just the # from the front of the lines you change.
- upload the entire folder to your webspace. I'm assuming that the hosting you're using is already set up to run perl scripts outside of cgi-bin; if it's not then you've got bigger problems than I can help you with. (The fact that your screenshot in >>1 has a cgi-bin folder does not bode well for you. Kareha and Wakaba both need to be run in the main area of your site, not from a cgi-bin.)
- your host will have instructions on any other changes you need to make to files regarding permissions that you will need to read before going any further; bug them for those.
- navigate to kareha.pl in your browser. If everything worked, a blank board will appear. If you've screwed up, then a error will pop up instead.