This post is in response to a request made at a recent training event. I promised that I would upload a video instruction on how to use sound editing software.
The software I work with is NCH's wavepad. There is a free version of this and a paid for version with more advanced features. The free version is very adequate for most of your requirements.
The first thing I would say if you are new to sound editors is that even if you are unfamiliar with the interface, if you know how to select, cut, copy, paste anything in a Word document, you can do this with a sound in a sound editor. The keyboard shortcuts are the same:
Ctrl+A = select all Ctrl+X = delete Ctrl+C = copy Ctrl+V = paste
Here are the first 7 videos to teach you a bit about how to do this
Introduction to the basics 1 - select and cut
Introduction to the basics 2 - splitting and trimming
Introduction to the basics 3 - saving files in different sound formats
Introduction to the basics 4 - Changing track speed
Introduction to the basics 5 - Changing track pitch
Introduction to the basics 6 -
Using slower speeds and looping to teach sections of a song
Introduction to the basics 7 - Copy your edited clip to a new file