Clip in hair extensions?

So, i've been trying to grow out my hair long, and every now and then I get a little trim and redo my layers to get all the dead ends off and stuff. My hairdresser cut off alot more than I asked, and now im back where I was last year when I started really growing it out. I've always wanted hair extensions, so I'd like to get them now, but the clip on ones. What do I need to know about the extensions? Are they alot of work? Will they look weird with my new layers I got put in? Thanks(: