Ubuntu is an excellent operating system, and Kino works perfectly for capturing DV video (at least if it supports your FireWire card). But watch me grow increasingly frustrated trying to find a video editor that actually works...
Yes, I know there's also AVIDemux and LightWorks, but AVIDemux lacks a timeline for assembling multiple clips in one video, and Lightworks has a steep learning curve, makes you sign up with an account to use it, and is not available in the Ubuntu Software Centre.
If the programs I showed work fine for you, then that's wonderful, but you have to realize that there's a good reason why people willingly spend $1500 on a Mac and $500 on a copy of Adobe Premiere to edit video, when they could theoretically do it for free on a much cheaper PC running Linux...