I am really fairly new to Linux but I have found that using a combination of Synaptic Package Manager & apt-get seems to work well. What one hangs up on the other usually can handle. I couldn't live without "apt-get -f install" though.

As far as I know defrag isn't necessary in Linux: http://www.linuxgazette.com/node/view/7434
Fsck seems to be run at least every 29 or 30 times that you bootup.