Help please (and a little about me lol)

Well, I know HTML doesn't work in the stories and stuff, so how do you strike things out, italics, bold, and underline things. I've seen it done, but I want to be able to. I won't be able to update either of my stories until i find out. Which kinda sucks but I need to know. Please and thank you. ^-^ On a better note, I made my school talent show. I can't wait, it's on May 2nd and I'm singing Our Song, By Taylor Swift. Anyway, if you can help me out, I'd greatly appreciate it. I hate the limit on words....It's VERY annoying! Peace!