The exclamation mark is arguably one of the most controversial pieces of English punctuation. Some writers love them; others hate them. The editors at Scribendi.com offer advice on when to use exclamation marks and when to avoid using them.
Interjections: A Guide to Using Interjections Effectively Podcast
Dialogue in a story should not be stiff, but should suit the characters. One way to add realism to dialogue is to use interjections. Ways to add realistic human touches using interjections are discussed in this podcast.