I have never done any video work before and a friend wants me to cut a 7 min. segment out of a 24 min video.

What is the best way to do it?

What format should it be for link to a webpage? mp4, avi ?

I'd like to do the same; I've cut the video in the timeline and want to keep the original format (mpeg-4) without having to re-render. Can I do this with Kdenlive?

Someone must know the answer to this! I have many video's only requiring a cut and no render - is this possible with Kdenlive?
If not, anyone know a Linux program which does this?

For anyone also requiring the same use Avidemux. It seems live Kdenlive is not capable of cutting without render.

You can try to use VidCrop. It's prog for crop video and also you can use zoom)It's helps me alot.)

Are we perhaps spamming here? Suggesting a commercial Windows program on an open source non-windows forum in the first posting is slightly suspicious.
http://virtualdub.org/ would be a Windows OpenSource program.

For cutting a clip in the timeline, select the clip there, move the marker to the position you want to cut the clip and right-click on the clip -> Cut clip.

Alternative, yet less accurate, is the scissor tool, to be found in the Tools menu.

Simon