I've just installed KDE4 on my Ubuntu (Hardy) system, just to see what it's like. Most of the time I just use whatever the default Gnome settings are.

Anyway, KDE mostly seems to be okay, but I can't work out why when I click on, say, the home folder in the start menu, it opens a terminal window instead of a file manager. I've tried to search for an answer but I haven't hit on the magic combination of keywords that will actually give me something useful. Can someone give me a hint as to what to look for? I'm a little too new to Linux to figure it out.

TIA!

thats totally weird.. maybe installing kde4 on gnome-hardy isn't a very good idea...
the filemanager is called dolphin..
you can change the broken menu entry by right clicking the kmenu button and enter the menu editor..
i would recommend to install kde 4.2.1 as this is the newest and stablest one with the most features for now.. (and therefore the only choice to give you an appropriate picture about what kde4 is capable of...)
but i dont know if its available for hardy...
you may try one of the kde4.2 live cds..