let me brief answer your questions :
> 1. How long does it take to get familiar with the software? Is it very difficult / time-consuming?
Few weeks ! Its not difficult ----
> 2. Is it self-explaining or would I need to attend a workshop to understand it?
Study manuals and all the stuff in
> 3. In how far do I need to be aware of html?
> 4. Are there greenstone experts that could assist me in setting up the library?
YES, but you can always write your problems in this mailing list.
> 5. In case greenstone should be too advanced, is there a different easy-to-use software you would recommend?
I don't know a software that is easier then greenstone
> I am very much hoping for a fast reply, as our time is short!
Everything takes its time ! Even paid solutions, so don't hurry too much !
Department of digitization
University library Bratislava