GoPro camera editing and stiching of files.

I recently picked up a gopro3 camera before I
left on a soaring vacation to Minden.

I did not have time to make a mount but I have quite
a few clips of hand holding the camera for 30-60 seconds
at a time and I would like to stich these together so it
will play as one video instead of 20 or more individual videos.

What software should I use? The gopro software or is there
something better/easier?

Next question formats, the gopro saves video in 3 formats, .THM, .LRV, and .MP4.

The .MP4 is the only one that plays on my computer, should I just
delete the other 2 formats of videos or is there a specific
purpose for the .THM and .LRV formats?

Thanks for any advice,

Joe Simmers EZ