Software to edit .mov files from a Canon 7D
VirtualDub is a very powerful video editor. However, it's not very intuitive to use it and it has a steep learning curve. On the plus side, there's a large internet community that supports it, so lots of online resources are available.

For your specific problem I've made a short tutorial below. I've done all steps in Windows XP with two .mov files from a Canon 550D. Unfortunately I failed to find an easy way of adjusting white balance with VirtualDub.
I've used various on-line resources to compile this tutorial. There might be a more optimal way of doing this, but I found this the most straight forward.

Installing VirtualDub + plugins


Download the VirtualDub 1.10.3.
Download ffinputdriver to enable loading .mov files.
Drag the VirtualDub folder to a convenient location. You don't need to install the program, it's click and run.
Place the contents of the plugin folder of ffinputdriver in the plugin folder found in the VirtualDub folder.
Start VirtualDub
First you'll need to convert your video to AVI. That's what VirtualDub works with natively. A warning: my 1280x720 .mov file of 25MB became a 600MB .avi file.
The transcoding speed is dependent on your machine.


Transcoding .mov to .avi


File -&gt; Open video file  
File -&gt; Save segmented AVI  
Repeat for all your files.  


Adjust Saturation


File -&gt; Open video file. Choose one of the AVI files you generated in the previous step.
The video file opens in two screens. The left is the original, the right one is the processed video. At first they should be identical. You can scale the video views by right-clicking on them and choosing an appropriate zoom percentage.
Go to Video and check if Full processing mode is on.
Go to Video -&gt; Filters -&gt; Add -&gt; HSV Adjust.
Adjust the saturation to your liking and hit OK. Hit OK again in the filter window.
Click File -&gt; Save segmented AVI... and save the edited file somewhere.
Repeat the process for all your videos in need of saturation adjustments.


Combine clips into one longer clip


File -&gt; Open video file. Choose the first file of your sequence.
File -&gt; Append AVI segment. The selected video file will be appended to the end of the open file.
Repeat this with all the video files.


Export to smaller file


Follow the steps outlined here.
From a 25MB .mov file I got a 600MB .avi file, which got transformed to a 2.7MB .mp4 file with the steps given in the linked tutorial.