Best way to edit an avi file, cut sections from the file and replace with other sections

I need to edit an avi file, as I say in the title, cut sections and replace with others. I know that this can be a bit dodgy, should i convert it to another file format and edit it then re-convert to avi? Or is there an easier way? What are the best programs to use?
Thanks in advance

 

I don't use mac. But really, any video editor should work. Did you get the iLife with ur mac? iMovie should be on your PC.

Hope I helped.

 

Thank you for your reply!
I actually solved my own problem. I did do the editing in iMovie, which i didn't know was possible. I head read a lot about avi's not behaving properly when edited, so i was worried about this. Actually, i think, but am not certain as I don't really know much about this, but i think iMovie converted my .avi into .mov when I imported it, which seemed to work OK. I am now facing another problem, exporting!! But i think I may have solved it. Thank you for your help.

 

For anyone else with this problem there is a mac version of avidemux which will also do all kinds of things with many many media file formats