Help in modifying sidebar

[mzaurrini]

I would like to modify the Popular content 'block' using it position on the side bar for having 5 'windows' on the more recent news of the 5 main categories of my website. as you can se at www.infomundi.it/wordpress I modified already the things but how can I insert the command that tells to every block to take the latest title from the category it depends?

To finish my site there is just a little problem I need to solve. I would like to make littler the carousel box...because with some resolutions all the left sidebar goes beyond the news in the main part of the page...how should I do...?
I know that I am asking a lot of thing but I am almost arrived at what I was looking for