first depending of your distro you while find the menu automaticaly added to your kde (if you do not see it immediatly try to log off then log in again)
second there is a ksomething to find application (kappfinder) that will let you scan your hard drive for softwares not in your kde menu
third possibility, manually edit the files in your ~/.kde directory. all teh menu items finish by desktop (like openoffice.desktop) so you could make a 'locate .desktop' if your updatedb is current
last (in my mind) is some tools like denu (works on gentoo but certainly for some other distro) that will help you create a personalised menu, but i tryed it and messup my menu so not my best option
distro like mandrake have a tool for menu
right click on the K from the menu and it will let you chose 'menu editor' a great tool for manually editing your kde menu
you can see a lot of options, my favorites are first kappfinder THEN menu editor to personalise
good luck
reup