It depends what you want to do. I really only need two basic functions, cut and splice. After recording a load of footage, I want to cut out the good bits and then sticth them together. I use two freeware programes fro this which are both very easy to use.
Cutting
Free Video Cutter
http://www.freevideocutter.com/
Watch video and note down time for start of cut and end of cut
Open free video cutter and open file that you want to cut
enter start time and end times for cut
enter name for cut video or leave the default
click start
If you want more than one cut from the video repeat the above process as many times as you like making sure you use different names for each cut
Splicing
Free Video Joiner
http://www.freevideojoiner.com/
Select the files you want to join together
Change the order if they are not in the order you want
Select the file type you want to output
Click join
Here is a sample. I cut the footage from several files and joined them into one
https://www.youtube.com/watch?v=QsXeWHm6Huw