If you want to edit your videos before uploading, then either record or pre-process the video fragments to Lagarith lossless codec (or anything without keyframes). This is much easier when editing.. You wont get the saving as other codecs (file size are normally about 40/50% of the original raw stream) , but you don't lose image quality from successive edits, and you can move forward back easily.
So generally i'll convert my captures into lossless, then assembly them with what ever app. For me, that's a really old app that came with my DVD burner (Video Studio 7).. It's awful.. But can be pretty quick to put the parts together. So when i'm done, I render the video out as XVID with Lame Mp3 for audio.