As others said, read the ELI5s.
Make sure you have all your keys, put them in a file (text will do just fine), and keep them safe and secure, with multiple backups in separate locations.
Then if you want to put one or more in a client like Jaxx, fine. But be aware that you can spend coins with services such as https://coinb.in/#settings which you can also download and run locally.
And yeah, Dough is a bad idea. 🙁