Hyphenating words

Hello, I'm writing my first novel and have a computer that is older than I am, so there is no Word Processing feature to it, merely Word Pad. The problem is that the lines look so messy on the right hand side, there can be long spaces before the next line. Example;

[and maintain their small space craft. While on their first solo flight without
[adults, they witnessed the last and final outcome of their war with The
[Unbekannt. For years they had been periodically bombed with fire
[destruction devices from a race that never identified itself, or at least were

If I'm going to send a disc of my novel to an agent, I would like for it to look fairly professional when he/she opens each chapter. It has been decades since I was in school, and I no longer remember the proper way to hyphenate words that are too long for the line. Where can I find rules about the proper places for hyphens to go in words? A word with an ing ending would be simple, but where, as an example, would I put a hyphen in the word 'destruction'?
Thank you in advance,
Miss V