Things that responsible OS X users should know
Through reading various Mac magazines and web-sites I've found out about a few useful things to care for my ibook:
Zapping pram Don't ask me exactly what it does, but I do it occasionally.
File System Check fsck - means running the command line which I find scary, but it does seem to find and correct things when I run it.
Useful programmes to have
The utility Console (in Applications/Utilites/ folder) that comes with OS x is useful when things are crashing to see what the OX thinks is happening. It records error messages which can then be used to search for help.
MacJanitor - runs the system maintenance jobs (cron jobs) that would run if your computer was on 24/7 at the press of a button. - Very useful for laptops which are usually switched off at night.
Liberer - cleans out libraries and caches of junk.
Monolingual - deletes all the extra language stuff on OS x to save space - got me about 600mb!!!