Can I Excerpt Posts?

Hey guys I can’t seem to figure out if this is possible in WP or not. Okay, so I make a post, and I have a ton of pictures in this post, but I only want to show, like, the first 30 words or so (just an example) but I want to have a “click here to read more” (sort of) link for the visitor to click on to read the whole post. I think this is call “excerpting” the post, but I can’t figure out how to use it, or if it’s even possible in WP. Anyone know?

Thanks.