I use Cinelerra for all my video editing needs. It is a great editor, but it still crashes occasionally and I found some importing and exporting difficulties, but you can workaround these problems.
If your source is a television recording taken on a DVD / hard drive recorder, then you can import your recording as shown here and here. After that, you should have a couple of m2v files to play with. I found Cinelerra to be less stable if I would edit these files straight away. You can render and save these files as DV files, and if you use that for editing, Cinelerra appears to be more stable.
If your source is a digital photo camera, then you may be able to read its avi files using a card reader. You may need a conversion as shown here to convert the audio from 8 to 16 bits, because Cinelerra currently does not like 8 bits audio in MJPEG files.
If you have a DV camera, then according to people on the internet, Kino is you best bet, but I have no experience in that area.
If playback does not work, make sure that the audio driver is set to ALSA instead of OSS.
I tried most of the formats found in Cinelerra, but they are somehow incompatible or have a huge file size. Therefore, I prefer to render and save the video seperately from the audio, and then use some postprocessing with other tools, in order to get the video in a size and format I want. The audio can be saved as a Microsoft wav file or an AC3 file. For the video I choose YUVMPEG. Then I can convert that to FLV for use on webpages as shown here. Or, for use on DVD's, I can convert them to an MPEG2 as shown here and multiplex it with its audio file as shown here.